更新日志¶
Python next¶
Release date: XXXX-XX-XX
Core and Builtins¶
gh-112388: Fix an error that was causing the parser to try to overwrite tokenizer errors. Patch by pablo Galindo
gh-112387: Fix error positions for decoded strings with backwards tokenize errors. Patch by Pablo Galindo
gh-112243: Don't include comments in f-string debug expressions. Patch by Pablo Galindo
gh-111654: Fix runtime crash when some error happens in opcode
LOAD_FROM_DICT_OR_DEREF
.gh-109181: Speed up
Traceback
object creation by lazily compute the line number. Patch by Pablo Galindogh-102388: Fix a bug where
iso2022_jp_3
andiso2022_jp_2004
codecs read out of boundsgh-111366: Fix an issue in the
codeop
that was causingSyntaxError
exceptions raised in the presence of invalid syntax to not contain precise error messages. Patch by Pablo Galindogh-111380: Fix a bug that was causing
SyntaxWarning
to appear twice when parsing if invalid syntax is encountered later. Patch by Pablo galindogh-94438: Fix a regression that prevented jumping across
is None
andis not None
when debugging. Patch by Savannah Ostrowski.gh-110938: Fix error messages for indented blocks with functions and classes with generic type parameters. Patch by Pablo Galindo
gh-109894: Fixed crash due to improperly initialized static
MemoryError
in subinterpreter.gh-110782: Fix crash when
typing.TypeVar
is constructed with a keyword argument. Patch by Jelle Zijlstra.gh-110696: Fix incorrect error message for invalid argument unpacking. Patch by Pablo Galindo
gh-110543: Fix regression in Python 3.12 where
types.CodeType.replace()
would produce a broken code object if called on a module or class code object that contains a comprehension. Patch by Jelle Zijlstra.gh-110514: Add
PY_THROW
tosys.setprofile()
eventsgh-110455: Guard
assert(tstate->thread_id > 0)
with#ifndef HAVE_PTHREAD_STUBS
. This allows for for pydebug builds to work under WASI which (currently) lacks thread support.gh-110259: Correctly identify the format spec in f-strings (with single or triple quotes) that have multiple lines in the expression part and include a formatting spec. Patch by Pablo Galindo
gh-110237: Fix missing error checks for calls to
PyList_Append
in_PyEval_MatchClass
.gh-109889: Fix the compiler's redundant NOP detection algorithm to skip over NOPs with no line number when looking for the next instruction's lineno.
gh-109853:
sys.path[0]
is now set correctly for subinterpreters.gh-105716: Subinterpreters now correctly handle the case where they have threads running in the background. Before, such threads would interfere with cleaning up and destroying them, as well as prevent running another script.
gh-109793: The main thread no longer exits prematurely when a subinterpreter is cleaned up during runtime finalization. The bug was a problem particularly because, when triggered, the Python process would always return with a 0 exitcode, even if it failed.
gh-109596: Fix some tokens in the grammar that were incorrectly marked as soft keywords. Also fix some repeated rule names and ensure that repeated rules are not allowed. Patch by Pablo Galindo
gh-109351: Fix crash when compiling an invalid AST involving a named (walrus) expression.
gh-109207: Fix a SystemError in
__repr__
of symtable entry object.gh-109179: Fix bug where the C traceback display drops notes from
SyntaxError
.gh-109052: Use the base opcode when comparing code objects to avoid interference from instrumentation
gh-88943: Improve syntax error for non-ASCII character that follows a numerical literal. It now points on the invalid non-ASCII character, not on the valid numerical literal.
gh-106931: Statically allocated string objects are now interned globally instead of per-interpreter. This fixes a situation where such a string would only be interned in a single interpreter. Normal string objects are unaffected.
Library¶
gh-112414: Fix regression in Python 3.12 where calling
repr()
on a module that had been imported using a custom loader could fail withAttributeError
. Patch by Alex Waygood.gh-112358: Revert change to
struct.Struct
initialization that broke some cases of subclassing.gh-94722: Fix bug where comparison between instances of
DocTest
fails if one of them hasNone
as its lineno.gh-112105: Make
readline.set_completer_delims()
work with libeditgh-111942: Fix SystemError in the TextIOWrapper constructor with non-encodable "errors" argument in non-debug mode.
gh-109538: Issue warning message instead of having
RuntimeError
be displayed when event loop has already been closed atStreamWriter.__del__()
.gh-111942: Fix crashes in
io.TextIOWrapper.reconfigure()
when pass invalid arguments, e.g. non-string encoding.gh-111460:
curses
: restore wide character support (includingcurses.unget_wch()
andget_wch()
) on macOS, which was unavailable due to a regression in Python 3.12.gh-103791:
contextlib.suppress
now supports suppressing exceptions raised as part of aBaseExceptionGroup
, in addition to the recent support forExceptionGroup
.gh-111804: Remove posix.fallocate() under WASI as the underlying posix_fallocate() is not available in WASI preview2.
gh-111841: Fix truncating arguments on an embedded null character in
os.putenv()
andos.unsetenv()
on Windows.gh-111541: Fix
doctest
forSyntaxError
not-builtin subclasses.gh-110894: Call loop exception handler for exceptions in
client_connected_cb
ofasyncio.start_server()
so that applications can handle it. Patch by Kumar Aditya.gh-111531: Fix reference leaks in
bind_class()
andbind_all()
methods oftkinter
widgets.gh-111356: Added
io.text_encoding()
,io.DEFAULT_BUFFER_SIZE
, andio.IncrementalNewlineDecoder
toio.__all__
.gh-111342: Fixed typo in
math.sumprod()
.gh-68166: Remove mention of not supported "vsapi" element type in
tkinter.ttk.Style.element_create()
. Add tests forelement_create()
and otherttk.Style
methods. Add examples forelement_create()
in the documentation.gh-79033: Another attempt at fixing
asyncio.Server.wait_closed()
. It now blocks until both conditions are true: the server is closed, and there are no more active connections. (This means that in some cases where in 3.12.0 this function would incorrectly have returned immediately, it will now block; in particular, when there are no active connections but the server hasn't been closed yet.)gh-111295: Fix
time
not checking for errors when initializing.gh-111253: Add error checking during
_socket
module init.gh-111251: Fix
_blake2
not checking for errors when initializing.gh-111174: Fix crash in
io.BytesIO.getbuffer()
called repeatedly for empty BytesIO.gh-111187: Postpone removal version for locale.getdefaultlocale() to Python 3.15.
gh-111159: Fix
doctest
output comparison for exceptions with notes.gh-110910: Fix invalid state handling in
asyncio.TaskGroup
andasyncio.Timeout
. They now raise proper RuntimeError if they are improperly used and are left in consistent state after this.gh-111092: Make turtledemo run without default root enabled.
gh-110488: Fix a couple of issues in
pathlib.PurePath.with_name()
: a single dot was incorrectly considered a valid name, and inPureWindowsPath
, a name with an NTFS alternate data stream, likea:b
, was incorrectly considered invalid.gh-110392: Fix
tty.setraw()
andtty.setcbreak()
: previously they returned partially modified list of the original tty attributes.tty.cfmakeraw()
andtty.cfmakecbreak()
now make a copy of the list of special characters before modifying it.gh-110590: Fix a bug in
_sre.compile()
whereTypeError
would be overwritten byOverflowError
when the code argument was a list of non-ints.gh-65052: Prevent
pdb
from crashing when trying to display undisplayable objectsgh-110519: Deprecation warning about non-integer number in
gettext
now alwais refers to the line in the user code where gettext function or method is used. Previously it could refer to a line ingettext
code.gh-110395: Ensure that
select.kqueue()
objects correctly appear as closed in forked children, to prevent operations on an invalid file descriptor.gh-110378:
contextmanager()
andasynccontextmanager()
context managers now close an invalid underlying generator object that yields more then one value.gh-110365: Fix
termios.tcsetattr()
bug that was overwritting existing errors during parsing integers fromterm
list.gh-109653: Fix a Python 3.12 regression in the import time of
random
. Patch by Alex Waygood.gh-110196: Add
__reduce__
method toIPv6Address
in order to keepscope_id
gh-110036: On Windows, multiprocessing
Popen.terminate()
now catchsPermissionError
and get the process exit code. If the process is still running, raise again thePermissionError
. Otherwise, the process terminated as expected: store its exit code. Patch by Victor Stinner.gh-110038: Fixed an issue that caused
KqueueSelector.select()
to not return all the ready events in some cases when a file descriptor is registered for both read and write.gh-109631:
re
functions such asre.findall()
,re.split()
,re.search()
andre.sub()
which perform short repeated matches can now be interrupted by user.gh-109747: Improve errors for unsupported look-behind patterns. Now re.error is raised instead of OverflowError or RuntimeError for too large width of look-behind pattern.
gh-109818: Fix
reprlib.recursive_repr()
not copying__type_params__
from decorated function.gh-109047:
concurrent.futures
: The executor manager thread now catches exceptions when adding an item to the call queue. During Python finalization, creating a new thread can now raiseRuntimeError
. Catch the exception and callterminate_broken()
in this case. Patch by Victor Stinner.gh-109782: Ensure the signature of
os.path.isdir()
is identical on all platforms. Patch by Amin Alaee.gh-109590:
shutil.which()
will prefer files with an extension inPATHEXT
if the given mode includesos.X_OK
on win32. If noPATHEXT
match is found, a file without an extension inPATHEXT
can be returned. This change will haveshutil.which()
act more similarly to previous behavior in Python 3.11.gh-109593: Avoid deadlocking on a reentrant call to the multiprocessing resource tracker. Such a reentrant call, though unlikely, can happen if a GC pass invokes the finalizer for a multiprocessing object such as SemLock.
gh-109613: Fix
os.stat()
andos.DirEntry.stat()
: check for exceptions. Previously, on Python built in debug mode, these functions could trigger a fatal Python error (and abort the process) when a function succeeded with an exception set. Patch by Victor Stinner.gh-109375: The
pdb
alias
command now prevents registering aliases without arguments.gh-107219: Fix a race condition in
concurrent.futures
. When a process in the process pool was terminated abruptly (while the future was running or pending), close the connection write end. If the call queue is blocked on sending bytes to a worker process, closing the connection write end interrupts the send, so the queue can be closed. Patch by Victor Stinner.gh-50644: Attempts to pickle or create a shallow or deep copy of
codecs
streams now raise a TypeError. Previously, copying failed with a RecursionError, while pickling produced wrong results that eventually caused unpickling to fail with a RecursionError.gh-108987: Fix
_thread.start_new_thread()
race condition. If a thread is created during Python finalization, the newly spawned thread now exits immediately instead of trying to access freed memory and lead to a crash. Patch by Victor Stinner.gh-108791: Improved error handling in
pdb
command line interface, making it produce more concise error messages.gh-105829: Fix concurrent.futures.ProcessPoolExecutor deadlock
gh-106584: Fix exit code for
unittest
if all tests are skipped. Patch by Egor Eliseev.gh-102956: Fix returning of empty byte strings after seek in zipfile module
gh-84867:
unittest.TestLoader
no longer loads test cases from exactunittest.TestCase
andunittest.FunctionTestCase
classes.gh-73561: Omit the interface scope from an IPv6 address when used as Host header by
http.client
.gh-86826:
zipinfo
now supports the full range of values in the TZ string determined by RFC 8536 and detects all invalid formats. Both Python and C implementations now raise exceptions of the same type on invalid data.bpo-41422: Fixed memory leaks of
pickle.Pickler
andpickle.Unpickler
involving cyclic references via the internal memo mapping.bpo-40262: The
ssl.SSLSocket.recv_into()
method no longer requires the buffer argument to implement__len__
and supports buffers with arbitrary item size.
Documentation¶
Tests¶
gh-110367: Make regrtest
--verbose3
option compatible with--huntrleaks -jN
options. The./python -m test -j1 -R 3:3 --verbose3
command now works as expected. Patch by Victor Stinner.gh-111165: Remove no longer used functions
run_unittest()
andrun_doctest()
from thetest.support
module.gh-110932: Fix regrtest if the
SOURCE_DATE_EPOCH
environment variable is defined: use the variable value as the random seed. Patch by Victor Stinner.gh-110995: test_gdb: Fix detection of gdb built without Python scripting support. Patch by Victor Stinner.
gh-110918: Test case matching patterns specified by options
--match
,--ignore
,--matchfile
and--ignorefile
are now tested in the order of specification, and the last match determines whether the test case be run or ignored.gh-110647: Fix test_stress_modifying_handlers() of test_signal. Patch by Victor Stinner.
gh-103053: Fix test_tools.test_freeze on FreeBSD: run "make distclean" instead of "make clean" in the copied source directory to remove also the "python" program. Patch by Victor Stinner.
gh-110167: Fix a deadlock in test_socket when server fails with a timeout but the client is still running in its thread. Don't hold a lock to call cleanup functions in doCleanups(). One of the cleanup function waits until the client completes, whereas the client could deadlock if it called addCleanup() in such situation. Patch by Victor Stinner.
gh-110267: Add tests for pickling and copying PyStructSequence objects. Patched by Xuehai Pan.
gh-110031: Skip test_threading tests using thread+fork if Python is built with Address Sanitizer (ASAN). Patch by Victor Stinner.
gh-110088: Fix test_asyncio timeouts: don't measure the maximum duration, a test should not measure a CI performance. Only measure the minimum duration when a task has a timeout or delay. Add
CLOCK_RES
totest_asyncio.utils
. Patch by Victor Stinner.gh-109974: Fix race conditions in test_threading lock tests. Wait until a condition is met rather than using
time.sleep()
with a hardcoded number of seconds. Patch by Victor Stinner.gh-110033: Fix
test_interprocess_signal()
oftest_signal
. Make sure that thesubprocess.Popen
object is deleted before the test raising an exception in a signal handler. Otherwise,Popen.__del__()
can get the exception which is logged asException ignored in: ...
and the test fails. Patch by Victor Stinner.gh-109594: Fix test_timeout() of test_concurrent_futures.test_wait. Remove the future which may or may not complete depending if it takes longer than the timeout ot not. Keep the second future which does not complete before wait() timeout. Patch by Victor Stinner.
gh-109972: Split test_gdb.py file into a test_gdb package made of multiple tests, so tests can now be run in parallel. Patch by Victor Stinner.
gh-103053: Skip test_freeze_simple_script() of test_tools.test_freeze if Python is built with
./configure --enable-optimizations
, which means with Profile Guided Optimization (PGO): it just makes the test too slow. The freeze tool is tested by many other CIs with other (faster) compiler flags. Patch by Victor Stinner.gh-109580: Skip
test_perf_profiler
if Python is built with ASAN, MSAN or UBSAN sanitizer. Python does crash randomly in this test on such build. Patch by Victor Stinner.gh-104736: Fix test_gdb on Python built with LLVM clang 16 on Linux ppc64le (ex: Fedora 38). Search patterns in gdb "bt" command output to detect when gdb fails to retrieve the traceback. For example, skip a test if
Backtrace stopped: frame did not save the PC
is found. Patch by Victor Stinner.
Build¶
gh-112088: Add
Tools/build/regen-configure.sh
script to regenerate theconfigure
with an Ubuntu container image. Thequay.io/tiran/cpython_autoconf:271
container image (tiran/cpython_autoconf) is no longer used. Patch by Victor Stinner.gh-111046: For wasi-threads, memory is now exported to fix compatibility issues with some wasm runtimes.
gh-103053: "make check-clean-src" now also checks if the "python" program is found in the source directory: fail with an error if it does exist. Patch by Victor Stinner.
gh-109191: Fix compile error when building with recent versions of libedit.
Windows¶
gh-111856: Fixes
fstat()
on file systems that do not support file ID requests. This includes FAT32 and exFAT.gh-111293: Fix
os.DirEntry.inode
dropping higher 64 bits of a file id on some filesystems on Windows.gh-110913: WindowsConsoleIO now correctly chunks large buffers without splitting up UTF-8 sequences.
gh-110437: Allows overriding the source of VC redistributables so that releases can be guaranteed to never downgrade between updates.
gh-109286: Update Windows installer to use SQLite 3.43.1.
macOS¶
gh-110950: Update macOS installer to include an upstream Tcl/Tk fix for the
Secure coding is not enabled for restorable state!
warning encountered in Tkinter on macOS 14 Sonoma.gh-111015: Ensure that IDLE.app and Python Launcher.app are installed with appropriate permissions on macOS builds.
gh-109286: Update macOS installer to use SQLite 3.43.1.
gh-71383: Update macOS installer to include an upstream Tcl/Tk fix for the
ttk::ThemeChanged
error encountered in Tkinter.gh-92603: Update macOS installer to include a fix accepted by upstream Tcl/Tk for a crash encountered after the first
tkinter.Tk()
instance is destroyed.
IDLE¶
bpo-35668: Add docstrings to the IDLE debugger module. Fix two bugs: initialize Idb.botframe (should be in Bdb); in Idb.in_rpc_code, check whether prev_frame is None before trying to use it. Greatly expand test_debugger.
C API¶
gh-112438: Fix support of format units "es", "et", "es#", and "et#" in nested tuples in
PyArg_ParseTuple()
-like functions.gh-109521:
PyImport_GetImporter()
now sets RuntimeError if it fails to getsys.path_hooks
orsys.path_importer_cache
or they are not list and dict correspondingly. Previously it could return NULL without setting error in obscure cases, crash or raise SystemError if these attributes have wrong type.
Python 3.12.0 final¶
Release date: 2023-10-02
Core and Builtins¶
gh-109823: Fix bug where compiler does not adjust labels when removing an empty basic block which is a jump target.
gh-109719: Fix missing jump target labels when compiler reorders cold/warm blocks.
gh-109627: Fix bug where the compiler does not assign a new jump target label to a duplicated small exit block.
Library¶
Documentation¶
gh-109209: The minimum Sphinx version required for the documentation is now 4.2.
Windows¶
gh-109991: Update Windows build to use OpenSSL 3.0.11.
macOS¶
gh-109991: Update macOS installer to use OpenSSL 3.0.11.
Tools/Demos¶
gh-109991: Update GitHub CI workflows to use OpenSSL 3.0.11 and multissltests to use 1.1.1w, 3.0.11, and 3.1.3.
Python 3.12.0 release candidate 3¶
Release date: 2023-09-18
Core and Builtins¶
gh-109496: On a Python built in debug mode,
Py_DECREF()
now calls_Py_NegativeRefcount()
if the object is a dangling pointer to deallocated memory: memory filled with0xDD
"dead byte" by the debug hook on memory allocators. The fix is to check the reference count before checking for_Py_IsImmortal()
. Patch by Victor Stinner.gh-109371: Deopted instructions correctly for tool initialization and modified the incorrect assertion in instrumentation, when a previous tool already sets INSTRUCTION events
gh-105658: Fix bug where the line trace of an except block ending with a conditional includes an excess event with the line of the conditional expression.
gh-109219: Fix compiling type param scopes that use a name which is also free in an inner scope.
gh-109341: Fix crash when compiling an invalid AST involving a
ast.TypeAlias
.gh-109195: Fix source location for the
LOAD_*
instruction preceding aLOAD_SUPER_ATTR
to load thesuper
global (or shadowing variable) so that it encompasses only the namesuper
and not the following parentheses.gh-109118: Disallow nested scopes (lambdas, generator expressions, and comprehensions) within PEP 695 annotation scopes that are nested within classes.
gh-109114: Relax the detection of the error message for invalid lambdas inside f-strings to not search for arbitrary replacement fields to avoid false positives. Patch by Pablo Galindo
gh-109118: Fix interpreter crash when a NameError is raised inside the type parameters of a generic class.
gh-108976: Fix crash that occurs after de-instrumenting a code object in a monitoring callback.
gh-108732: Make iteration variables of module- and class-scoped comprehensions visible to pdb and other tools that use
frame.f_locals
again.gh-108959: Fix caret placement for error locations for subscript and binary operations that involve non-semantic parentheses and spaces. Patch by Pablo Galindo
Library¶
gh-108682: Enum: require
names=()
ortype=...
to create an empty enum using the functional syntax.gh-108843: Fix an issue in
ast.unparse()
when unparsing f-strings containing many quote types.
Documentation¶
Tests¶
gh-109396: Fix
test_socket.test_hmac_sha1()
in FIPS mode. Use a longer key: FIPS mode requires at least of at least 112 bits. The previous key was only 32 bits. Patch by Victor Stinner.gh-104736: Fix test_gdb on Python built with LLVM clang 16 on Linux ppc64le (ex: Fedora 38). Search patterns in gdb "bt" command output to detect when gdb fails to retrieve the traceback. For example, skip a test if
Backtrace stopped: frame did not save the PC
is found. Patch by Victor Stinner.gh-109237: Fix
test_site.test_underpth_basic()
when the working directory contains at least one non-ASCII character: encode the._pth
file to UTF-8 and enable the UTF-8 Mode to use UTF-8 for the child process stdout. Patch by Victor Stinner.gh-109230: Fix
test_pyexpat.test_exception()
: it can now be run from a directory different than Python source code directory. Before, the test failed in this case. Skip the test if Modules/pyexpat.c source is not available. Skip also the test on Python implementations other than CPython. Patch by Victor Stinner.gh-109015: Fix test_asyncio, test_imaplib and test_socket tests on FreeBSD if the TCP blackhole is enabled (
sysctl net.inet.tcp.blackhole
). Skip the few tests which failed withETIMEDOUT
which such non standard configuration. Currently, the FreeBSD GCP image enables TCP and UDP blackhole (sysctl net.inet.tcp.blackhole=2
andsysctl net.inet.udp.blackhole=1
). Patch by Victor Stinner.gh-91960: Skip
test_gdb
if gdb is unable to retrieve Python frame objects: if a frame is<optimized out>
. When Python is built with "clang -Og", gdb can fail to retrive the frame parameter of_PyEval_EvalFrameDefault()
. In this case, tests likepy_bt()
are likely to fail. Without getting access to Python frames,python-gdb.py
is mostly clueless on retrieving the Python traceback. Moreover,test_gdb
is no longer skipped on macOS if Python is built with Clang. Patch by Victor Stinner.gh-108962: Skip
test_tempfile.test_flags()
ifchflags()
fails with "OSError: [Errno 45] Operation not supported" (ex: on FreeBSD 13). Patch by Victor Stinner.gh-108851: Fix
test_tomllib
recursion tests for WASI buildbots: reduce the recursion limit and compute the maximum nested array/dict depending on the current available recursion limit. Patch by Victor Stinner.gh-108851: Add
get_recursion_available()
andget_recursion_depth()
functions to thetest.support
module. Patch by Victor Stinner.gh-108834: Add
--fail-rerun option
option to regrtest: if a test failed when then passed when rerun in verbose mode, exit the process with exit code 2 (error), instead of exit code 0 (success). Patch by Victor Stinner.gh-108834: Rename regrtest
--verbose2
option (-w
) to--rerun
. Keep--verbose2
as a deprecated alias. Patch by Victor Stinner.gh-108834: When regrtest reruns failed tests in verbose mode (
./python -m test --rerun
), tests are now rerun in fresh worker processes rather than being executed in the main process. If a test does crash or is killed by a timeout, the main process can detect and handle the killed worker process. Tests are rerun in parallel if the-jN
option is used to run tests in parallel. Patch by Victor Stinner.gh-103186: Suppress and assert expected RuntimeWarnings in test_sys_settrace.py
Build¶
gh-108740: Fix a race condition in
make regen-all
. Thedeepfreeze.c
source and files generated by Argument Clinic are now generated or updated before generating "global objects". Previously, some identifiers may miss depending on the order in which these files were generated. Patch by Victor Stinner.
Python 3.12.0 release candidate 2¶
Release date: 2023-09-05
Security¶
gh-108310: Fixed an issue where instances of
ssl.SSLSocket
were vulnerable to a bypass of the TLS handshake and included protections (like certificate verification) and treating sent unencrypted data as if it were post-handshake TLS encrypted data. Security issue reported as CVE-2023-40217 by Aapo Oksman. Patch by Gregory P. Smith.gh-107774: PEP 669 specifies that
sys.monitoring.register_callback
will generate an audit event. Pre-releases of Python 3.12 did not generate the audit event. This is now fixed.
Core and Builtins¶
gh-108520: Fix
multiprocessing.synchronize.SemLock.__setstate__()
to properly initializemultiprocessing.synchronize.SemLock._is_fork_ctx
. This fixes a regression when passing a SemLock accross nested processes.Rename
multiprocessing.synchronize.SemLock.is_fork_ctx
tomultiprocessing.synchronize.SemLock._is_fork_ctx
to avoid exposing it as public API.gh-108654: Restore locals shadowed by an inlined comprehension if the comprehension raises an exception.
gh-108487: Change an assert that would cause a spurious crash in a devious case that should only trigger deoptimization.
gh-106176: Use a
WeakValueDictionary
to track the lists containing the modules each thread is currently importing. This helps avoid a reference leak from keeping the list around longer than necessary. Weakrefs are used as GC can't interrupt the cleanup.gh-107901: Fix missing line number on
JUMP_BACKWARD
at the end of a for loop.gh-108390: Raise an exception when setting a non-local event (
RAISE
,EXCEPTION_HANDLED
, etc.) insys.monitoring.set_local_events
.Fixes crash when tracing in recursive calls to Python classes.
gh-91051: Fix abort / segfault when using all eight type watcher slots, on platforms where
char
is signed by default.gh-107724: In pre-release versions of 3.12, up to rc1, the sys.monitoring callback function for the
PY_THROW
event was missing the third, exception argument. That is now fixed.gh-107080: Trace refs builds (
--with-trace-refs
) were crashing when used with isolated subinterpreters. The problematic global state has been isolated to each interpreter. Other fixing the crashes, this change does not affect users.gh-77377: Ensure that multiprocessing synchronization objects created in a fork context are not sent to a different process created in a spawn context. This changes a segfault into an actionable RuntimeError in the parent process.
Library¶
gh-108469:
ast.unparse()
now supports new f-string syntax introduced in Python 3.12. Note that the f-string quotes are reselected for simplicity under the new syntax. (Patch by Steven Sun)gh-108682: Enum: raise
TypeError
ifsuper().__new__()
is called from a custom__new__
.gh-108295: Fix crashes related to use of weakrefs on
typing.TypeVar
.gh-64662: Fix support for virtual tables in
sqlite3.Connection.iterdump()
. Patch by Aviv Palivoda.gh-108111: Fix a regression introduced in gh-101251 for 3.12, resulting in an incorrect offset calculation in
gzip.GzipFile.seek()
.gh-105736: Harmonized the pure Python version of
OrderedDict
with the C version. Now, both versions set up their internal state in__new__
. Formerly, the pure Python version did the set up in__init__
.gh-108083: Fix bugs in the constructor of
sqlite3.Connection
andsqlite3.Connection.close()
where exceptions could be leaked. Patch by Erlend E. Aasland.gh-107963: Fix
multiprocessing.set_forkserver_preload()
to check the given list of modules names. Patch by Donghee Na.gh-106242: Fixes
os.path.normpath()
to handle embedded null characters without truncating the path.gh-107913: Fix possible losses of
errno
andwinerror
values inOSError
exceptions if they were cleared or modified by the cleanup code before creating the exception object.gh-107845:
tarfile.data_filter()
now takes the location of symlinks into account when determining their target, so it will no longer reject some valid tarballs withLinkOutsideDestinationError
.gh-107805: Fix signatures of module-level generated functions in
turtle
.gh-107715: Fix
doctest.DocTestFinder.find()
in presence of class names with special characters. Patch by Gertjan van Zwieten.gh-100814: Passing a callable object as an option value to a Tkinter image now raises the expected TclError instead of an AttributeError.
gh-106684: Close
asyncio.StreamWriter
when it is not closed by application leading to memory leaks. Patch by Kumar Aditya.gh-107396: tarfiles; Fixed use before assignment of self.exception for gzip decompression
gh-106052:
re
module: fix the matching of possessive quantifiers in the case of a subpattern containing backtracking.gh-100061: Fix a bug that causes wrong matches for regular expressions with possessive qualifier.
gh-99203: Restore following CPython <= 3.10.5 behavior of
shutil.make_archive()
: do not create an empty archive ifroot_dir
is not a directory, and, in that case, raiseFileNotFoundError
orNotADirectoryError
regardless offormat
choice. Beyond the brought-back behavior, the function may now also raise these exceptions indry_run
mode.
Documentation¶
gh-105052: Update
timeit
doc to specify that time in seconds is just the default.
Tests¶
gh-89392: Removed support of
test_main()
function in tests. They now always use normal unittest test runner.gh-108388: Convert test_concurrent_futures to a package of 7 sub-tests. Patch by Victor Stinner.
gh-108388: Split test_multiprocessing_fork, test_multiprocessing_forkserver and test_multiprocessing_spawn into test packages. Each package is made of 4 sub-tests: processes, threads, manager and misc. It allows running more tests in parallel and so reduce the total test duration. Patch by Victor Stinner.
gh-105776: Fix test_cppext when the C compiler command
-std=c11
option: remove-std=
options from the compiler command. Patch by Victor Stinner.gh-107178: Add the C API test for functions in the Mapping Protocol, the Sequence Protocol and some functions in the Object Protocol.
Build¶
Windows¶
gh-107565: Update Windows build to use OpenSSL 3.0.10.
gh-106242: Fixes
realpath()
to behave consistently when passed a path containing an embedded null character on Windows. In strict mode, it now raisesOSError
instead of the unexpectedValueError
, and in non-strict mode will make the path absolute.gh-106844: Fix integer overflow and truncating by the null character in
_winapi.LCMapStringEx()
which affectsntpath.normcase()
.
macOS¶
gh-107565: Update macOS installer to use OpenSSL 3.0.10.
Tools/Demos¶
C API¶
gh-107916: C API functions
PyErr_SetFromErrnoWithFilename()
,PyErr_SetExcFromWindowsErrWithFilename()
andPyErr_SetFromWindowsErrWithFilename()
save now the error code before callingPyUnicode_DecodeFSDefault()
.gh-107915: Such C API functions as
PyErr_SetString()
,PyErr_Format()
,PyErr_SetFromErrnoWithFilename()
and many others no longer crash or ignore errors if it failed to format the error message or decode the filename. Instead, they keep a corresponding error.gh-107810: Improve
DeprecationWarning
for uses ofPyType_Spec
with metaclasses that have customtp_new
.
Python 3.12.0 release candidate 1¶
Release date: 2023-08-05
Security¶
gh-102988: Reverted the
email.utils
security improvement change released in 3.12beta4 that unintentionally causedemail.utils.getaddresses
to fail to parse email addresses with a comma in the quoted name field. See gh-106669.gh-102509: Start initializing
ob_digit
during creation ofPyLongObject
objects. Patch by Illia Volochii.
Core and Builtins¶
gh-107263: Increase C recursion limit for functions other than the main interpreter from 800 to 1500. This should allow functions like
list.__repr__
andjson.dumps
to handle all the inputs that they could prior to 3.12gh-104432: Fix potential unaligned memory access on C APIs involving returned sequences of
char *
pointers within thegrp
andsocket
modules. These were revealed using a-fsaniziter=alignment
build on ARM macOS. Patch by Christopher Chavez.gh-106898: Add the exception as the third argument to
PY_UNIND
callbacks insys.monitoring
. This makes thePY_UNWIND
callback consistent with the other exception hanlding callbacks.gh-106895: Raise a
ValueError
when a monitoring callback funtion returnsDISABLE
for events that cannot be disabled locally.gh-106897: Add a
RERAISE
event tosys.monitoring
, which occurs when an exception is reraised, either explicitly by a plainraise
statement, or implicitly in anexcept
orfinally
block.gh-104621: Unsupported modules now always fail to be imported.
gh-106917: Fix classmethod-style
super()
method calls (i.e., where the second argument tosuper()
, or the implied second argument drawn fromself/cls
in the case of zero-arg super, is a type) when the target of the call is not a classmethod.gh-105699: Python no longer crashes due an infrequent race when initialzing per-interpreter interned strings. The crash would manifest when the interpreter was finalized.
gh-105699: Python no longer crashes due to an infrequent race in setting
Py_FileSystemDefaultEncoding
andPy_FileSystemDefaultEncodeErrors
(both deprecated), when simultaneously initializing two isolated subinterpreters. Now they are only set during runtime initialization.gh-106092: Fix a segmentation fault caused by a use-after-free bug in
frame_dealloc
when the trashcan delays the deallocation of aPyFrameObject
.gh-106719: No longer suppress arbitrary errors in the
__annotations__
getter and setter in the type and module types.gh-106723: Propagate
frozen_modules
to multiprocessing spawned process interpreters.gh-105235: Prevent out-of-bounds memory access during
mmap.find()
calls.
Library¶
gh-107077: Seems that in some conditions, OpenSSL will return
SSL_ERROR_SYSCALL
instead ofSSL_ERROR_SSL
when a certification verification has failed, but the error parameters will still containERR_LIB_SSL
andSSL_R_CERTIFICATE_VERIFY_FAILED
. We are now detecting this situation and raising the appropiatessl.SSLCertVerificationError
. Patch by Pablo Galindogh-107576: Fix
types.get_original_bases()
to only return__orig_bases__
if it is present oncls
directly. Patch by James Hilton-Balfe.gh-46376: Prevent memory leak and use-after-free when using pointers to pointers with ctypes
gh-62519: Make
gettext.pgettext()
search plural definitions when translation is not found.gh-83006: Document behavior of
shutil.disk_usage()
for non-mounted filesystems on Unix.gh-106186: Do not report
MultipartInvariantViolationDefect
defect when theemail.parser.Parser
class is used to parse emails withheadersonly=True
.gh-105002: Fix invalid result from
PurePath.relative_to()
method when attempting to walk a "..
" segment in other with walk_up enabled. AValueError
exception is now raised in this case.gh-106831: Fix potential missing
NULL
check ofd2i_SSL_SESSION
result in_ssl.c
.gh-106774: Update the bundled copy of pip to version 23.2.1.
gh-106752: Fixed several bugs in zipfile.Path, including: in
Path.match`, Windows separators are no longer honored (and never were meant to be); Fixed ``name
/suffix
/suffixes
/stem
operations when no filename is present and the Path is not at the root of the zipfile; Reworked glob for performance and more correct matching behavior.gh-106530: Revert a change to
colorsys.rgb_to_hls()
that caused division by zero for certain almost-white inputs. Patch by Terry Jan Reedy.gh-106403: Instances of
typing.TypeVar
,typing.ParamSpec
,typing.ParamSpecArgs
,typing.ParamSpecKwargs
, andtyping.TypeVarTuple
once again support weak references, fixing a regression introduced in Python 3.12.0 beta 1. Patch by Jelle Zijlstra.gh-106350: Detect possible memory allocation failure in the libtommath function
mp_init()
used by the_tkinter
module.gh-106263: Fix crash when calling
repr
with a manually constructed SignalDict object. Patch by Charlie Zhao.gh-105626: Change the default return value of
http.client.HTTPConnection.get_proxy_response_headers()
to beNone
and not{}
.bpo-18319: Ensure
gettext(msg)
retrieve translations even if a plural form exists. In other words:gettext(msg) == ngettext(msg, '', 1)
.
Documentation¶
gh-107305: Add documentation for
PyInterpreterConfig
andPy_NewInterpreterFromConfig()
. Also clarify some of the nearby docs relative to per-interpreter GIL.gh-107008: Document the
curses
module variablesLINES
andCOLS
.gh-106948: Add a number of standard external names to
nitpick_ignore
.gh-54738: Add documentation on how to localize the
argparse
module.
Tests¶
gh-107237:
test_logging
: Fixtest_udp_reconnection()
by increasing the timeout from 100 ms to 5 minutes (LONG_TIMEOUT). Patch by Victor Stinner.gh-106714: test_capi: Fix test_no_FatalError_infinite_loop() to no longer write a coredump, by using test.support.SuppressCrashReport. Patch by Victor Stinner.
gh-104090: Avoid creating a reference to the test object in
collectedDurations()
.gh-106752: Moved tests for
zipfile.Path
intoLib/test/test_zipfile/_path
. Madezipfile._path
a package.
Build¶
Windows¶
gh-99079: Update Windows build to use OpenSSL 3.0.9
macOS¶
gh-99079: Update macOS installer to use OpenSSL 3.0.9.
Tools/Demos¶
gh-106970: Fix bugs in the Argument Clinic
destination <name> clear
command; the destination buffers would never be cleared, and thedestination
directive parser would simply continue to the fault handler after processing the command. Patch by Erlend E. Aasland.gh-103186:
freeze
now fetchesCONFIG_ARGS
from the original CPython instance the Makefile uses to call utility scripts. Patch by Ijtaba Hussain.
C API¶
gh-107226:
PyModule_AddObjectRef()
is now only available in the limited API version 3.10 or later.
Python 3.12.0 beta 4¶
Release date: 2023-07-11
Security¶
gh-102988: CVE-2023-27043: Prevent
email.utils.parseaddr()
andemail.utils.getaddresses()
from returning the realname portion of an invalid RFC2822 email header in the email address portion of the 2-tuple returned after being parsed byemail._parseaddr.AddressList
.
Core and Builtins¶
gh-106396: When the format specification of an f-string expression is empty, the parser now generates an empty
ast.JoinedStr
node for it instead of an one-elementast.JoinedStr
with an empty stringast.Constant
.gh-106145: Make
end_lineno
andend_col_offset
required ontype_param
ast nodes.gh-105979: Fix crash in
_imp.get_frozen_object()
due to improper exception handling.gh-98931: Ensure custom
SyntaxError
error messages are raised for invalid imports with multiple targets. Patch by Pablo Galindogh-105908: Fixed bug where gh-99111 breaks future import
barry_as_FLUFL
in the Python REPL.gh-105340: Include the comprehension iteration variable in
locals()
inside a module- or class-scope comprehension.gh-105486: Change the repr of
ParamSpec
list of args intypes.GenericAlias
.
Library¶
gh-106524: Fix crash in
_sre.template()
with templates containing invalid group indices.gh-106510: Improve debug output for atomic groups in regular expressions.
gh-106503: Fix ref cycle in
asyncio._SelectorSocketTransport
by removing_write_ready
inclose
.gh-105497: Fix flag mask inversion when unnamed flags exist.
gh-90876: Prevent
multiprocessing.spawn
from failing to import in environments wheresys.executable
isNone
. This regressed in 3.11 with the addition of support for path-like objects in multiprocessing.gh-106292: Check for an instance-dict cached value in the
__get__()
method offunctools.cached_property()
. This better matches the pre-3.12 behavior and improves compatibility for users subclassingfunctools.cached_property()
and adding a__set__()
method.gh-106330: Fix incorrect matching of empty paths in
pathlib.PurePath.match()
. This bug was introduced in Python 3.12.0 beta 1.gh-102541: Make pydoc.doc catch bad module ImportError when output stream is not None.
gh-106152: Added PY_THROW event hook for
cProfile
for generatorsgh-106075: Added
asyncio.taskgroups.__all__
toasyncio.__all__
for export in star imports.gh-105987: Fix crash due to improper reference counting in
asyncio
eager task factory internal routines.gh-105974: Fix bug where a
typing.Protocol
class that had one or more non-callable members would raiseTypeError
whenissubclass()
was called against it, even if it defined a custom__subclasshook__
method. The behaviour in Python 3.11 and lower -- which has now been restored -- was not to raiseTypeError
in these situations if a custom__subclasshook__
method was defined. Patch by Alex Waygood.gh-96145: Reverted addition of
json.AttrDict
.gh-105497: Fix flag inversion when alias/mask members exist.
gh-104554: Add RTSPS scheme support in urllib.parse
gh-94777: Fix hanging
multiprocessing
ProcessPoolExecutor
when a child process crashes while data is being written in the call queue.
Documentation¶
gh-106232: Make timeit doc command lines compatible with Windows by using double quotes for arguments. This works on linux and macOS also.
Tests¶
gh-101634: When running the Python test suite with
-jN
option, if a worker stdout cannot be decoded from the locale encoding report a failed testn so the exitcode is non-zero. Patch by Victor Stinner.
Build¶
gh-106118: Fix compilation for platforms without
O_CLOEXEC
. The issue was introduced with Python 3.12b1 in gh-103295. Patch by Erlend Aasland.gh-104692: Include
commoninstall
as a prerequisite forbininstall
This ensures that
commoninstall
is completed beforebininstall
is started when parallel builds are used (make -j install
), and so thepython3
symlink is only installed after all standard library modules are installed.
Tools/Demos¶
gh-106359: Argument Clinic now explicitly forbids "kwarg splats" in function calls used as annotations.
C API¶
gh-105227: The new
PyType_GetDict()
provides the dictionary for the given type object that is normally exposed bycls.__dict__
. Normally it's sufficient to usetp_dict
, but for the static builtin typestp_dict
is now alwaysNULL
.PyType_GetDict()
provides the correct dict object instead.
Python 3.12.0 beta 3¶
Release date: 2023-06-19
Core and Builtins¶
gh-105840: Fix possible crashes when specializing function calls with too many
__defaults__
.gh-105831: Fix an f-string bug, where using a debug expression (the
=
sign) that appears in the last line of a file results to the debug buffer that holds the expression text being one character too small.gh-105800: Correctly issue
SyntaxWarning
in f-strings if invalid sequences are used. Patch by Pablo Galindogh-105587: The runtime can't guarantee that immortal objects will not be mutated by Extensions. Thus, this modifies _PyStaticObject_CheckRefcnt to warn instead of asserting.
gh-105564: Don't include artificil newlines in the
line
attribute of tokens in the APIs of thetokenize
module. Patch by Pablo Galindogh-105549: Tokenize separately
NUMBER
andNAME
tokens that are not ambiguous. Patch by Pablo Galindo.gh-105588: Fix an issue that could result in crashes when compiling malformed
ast
nodes.gh-105375: Fix bugs in the
builtins
module where exceptions could end up being overwritten.gh-105375: Fix bug in the compiler where an exception could end up being overwritten.
gh-105375: Improve error handling in
PyUnicode_BuildEncodingMap()
where an exception could end up being overwritten.gh-105435: Fix spurious newline character if file ends on a comment without a newline. Patch by Pablo Galindo
gh-105390: Correctly raise
tokenize.TokenError
exceptions instead ofSyntaxError
for tokenize errors such as incomplete input. Patch by Pablo Galindogh-104812: The "pending call" machinery now works for all interpreters, not just the main interpreter, and runs in all threads, not just the main thread. Some calls are still only done in the main thread, ergo in the main interpreter. This change does not affect signal handling nor the existing public C-API (
Py_AddPendingCall()
), which both still only target the main thread. The new functionality is meant strictly for internal use for now, since consequences of its use are not well understood yet outside some very restricted cases. This change brings the capability in line with the intention when the state was made per-interpreter several years ago.
Library¶
gh-105808: Fix a regression introduced in gh-101251 for 3.12, causing
gzip.GzipFile.flush()
to not flush the compressor (nor pass along thezip_mode
argument).gh-104799: Enable
ast.unparse()
to unparse function and class definitions created without the newtype_params
field from PEP 695. Patch by Jelle Zijlstra.gh-105745: Fix
webbrowser.Konqueror.open
method.gh-105375: Fix a bug in
_Unpickler_SetInputStream()
where an exception could end up being overwritten in case of failure.gh-105375: Fix bugs in
sys
where exceptions could end up being overwritten because of deferred error handling.gh-105605: Harden
pyexpat
error handling during module initialisation to prevent exceptions from possibly being overwritten, and objects from being dereferenced twice.gh-105375: Fix bug in
decimal
where an exception could end up being overwritten.gh-105375: Fix bugs in
_datetime
where exceptions could be overwritten in case of module initialisation failure.gh-105375: Fix bugs in
_ssl
initialisation which could lead to leaked references and overwritten exceptions.gh-105375: Fix a bug in
array.array
where an exception could end up being overwritten.gh-105375: Fix bugs in
_ctypes
where exceptions could end up being overwritten.gh-105375: Fix a bug in the
posix
module where an exception could be overwritten.gh-105375: Fix bugs in
_elementtree
where exceptions could be overwritten.gh-105375: Fix bugs in
zoneinfo
where exceptions could be overwritten.gh-105375: Fix bugs in
errno
where exceptions could be overwritten.gh-105375: Fix bugs in
pickle
where exceptions could be overwritten.gh-105375: Fix a bug in
sqlite3
where an exception could be overwritten in thecollation
callback.gh-105332: Revert pickling method from by-name back to by-value.
gh-104310: In the beta 1 release we added a utility function for extension module authors, to use when testing their module for support in multiple interpreters or under a per-interpreter GIL. The name of that function has changed from
allowing_all_extensions
to_incompatible_extension_module_restrictions
. The default for the "disable_check" argument has change fromTrue
toFalse
, to better match the new function name.gh-104996: Improve performance of
pathlib.PurePath
initialisation by deferring joining of paths when multiple arguments are given.gh-102541: Hide traceback in
help()
prompt, when import failed.
Tests¶
gh-105084: When the Python build is configured
--with-wheel-pkg-dir
, tests requiring thesetuptools
andwheel
wheels will search for the wheels inWHEEL_PKG_DIR
.
Windows¶
gh-105436: Ensure that an empty environment block is terminated by two null characters, as is required by Windows.
C API¶
gh-105375: Fix a bug in
PyErr_WarnExplicit()
where an exception could end up being overwritten if the API failed internally.gh-105603: We've renamed the new (in 3.12)
PyInterpreterConfig.own_gil
toPyInterpreterConfig.gil
and changed the meaning of the value from "bool" to an integer with supported values ofPyInterpreterConfig_DEFAULT_GIL
,PyInterpreterConfig_SHARED_GIL
, andPyInterpreterConfig_OWN_GIL
. The default is "shared".gh-105387: In the limited C API version 3.12,
Py_INCREF()
andPy_DECREF()
functions are now implemented as opaque function calls to hide implementation details. Patch by Victor Stinner.gh-103968:
PyType_FromMetaclass()
now allows metaclasses withtp_new
set toNULL
.
Python 3.12.0 beta 2¶
Release date: 2023-06-06
Security¶
Core and Builtins¶
gh-105259: Don't include newline character for trailing
NEWLINE
tokens emitted in thetokenize
module. Patch by Pablo Galindogh-105324: Fix the main function of the
tokenize
module when reading fromsys.stdin
. Patch by Pablo Galindogh-98963: Restore the ability for a subclass of
property
to define__slots__
or otherwise be dict-less by ignoring failures to set a docstring on such a class. This behavior had regressed in 3.12beta1. AnAttributeError
where there had not previously been one was disruptive to existing code.gh-105194: Do not escape with backslashes f-string format specifiers. Patch by Pablo Galindo
gh-105162: Fixed bug in generator.close()/throw() where an inner iterator would be ignored when the outer iterator was instrumented.
gh-105164: Ensure annotations are set up correctly if the only annotation in a block is within a
match
block. Patch by Jelle Zijlstra.gh-104799: Attributes of
ast
nodes that are lists now default to the empty list if omitted. This means that some code that previously raisedTypeError
when the AST node was used will now proceed with the empty list instead. Patch by Jelle Zijlstra.gh-105035: Fix
super()
calls on types with customtp_getattro
implementation (e.g. meta-types.)gh-105017: Show CRLF lines in the tokenize string attribute in both NL and NEWLINE tokens. Patch by Marta Gómez.
gh-105013: Fix handling of multiline parenthesized lambdas in
inspect.getsource()
. Patch by Pablo Galindogh-105017: Do not include an additional final
NL
token when parsing files having CRLF lines. Patch by Marta Gómez.gh-104976: Ensure that trailing
DEDENT
tokenize.TokenInfo
objects emitted by thetokenize
module are reported as in Python 3.11. Patch by Pablo Galindogh-104972: Ensure that the
line
attribute intokenize.TokenInfo
objects in thetokenize
module are always correct. Patch by Pablo Galindogh-104955: Fix signature for the new
__release_buffer__()
slot. Patch by Jelle Zijlstra.gh-104690: Starting new threads and process creation through
os.fork()
during interpreter shutdown (such as fromatexit
handlers) is no longer supported. It can lead to race condition between the main Python runtime thread freeing thread states while internalthreading
routines are trying to allocate and use the state of just created threads. Or forked children trying to use the mid-shutdown runtime and thread state in the child process.gh-104879: Fix crash when accessing the
__module__
attribute of type aliases defined outside a module. Patch by Jelle Zijlstra.gh-104825: Tokens emitted by the
tokenize
module do not include an implicit\n
character in theline
attribute anymore. Patch by Pablo Galindo
Library¶
gh-105280: Fix bug where
isinstance([], collections.abc.Mapping)
could evaluate toTrue
if garbage collection happened at the wrong time. The bug was caused by changes to the implementation oftyping.Protocol
in Python 3.12.gh-105239: Fix longstanding bug where
issubclass(object, typing.Protocol)
would evaluate toTrue
in some edge cases. Patch by Alex Waygood.gh-105080: Fixed inconsistent signature on derived classes for
inspect.signature()
gh-105144: Fix a recent regression in the
typing
module. The regression meant that doingclass Foo(X, typing.Protocol)
, whereX
was a class that hadabc.ABCMeta
as its metaclass, would then cause subsequentisinstance(1, X)
calls to erroneously raiseTypeError
. Patch by Alex Waygood.gh-105113: Improve performance of
pathlib.PurePath.match()
by compiling anre.Pattern
object for the entire pattern.gh-101588: Deprecate undocumented copy/deepcopy/pickle support for itertools.
gh-103631: Fix
pathlib.PurePosixPath(pathlib.PureWindowsPath(...))
not converting path separators to restore 3.11 compatible behavior.gh-104947: Make comparisons between
pathlib.PureWindowsPath
objects consistent across Windows and Posix to match 3.11 behavior.gh-104935: Fix bugs with the interaction between
typing.runtime_checkable()
andtyping.Generic
that were introduced by the PEP 695 implementation. Patch by Jelle Zijlstra.gh-104874: Document the
__name__
and__supertype__
attributes oftyping.NewType
. Patch by Jelle Zijlstra.gh-104799: Adjust the location of the (see PEP 695)
type_params
field onast.ClassDef
,ast.AsyncFunctionDef
, andast.FunctionDef
to better preserve backward compatibility. Patch by Jelle Zijlstragh-104797: Allow
typing.Protocol
classes to inherit fromcollections.abc.Buffer
. Patch by Jelle Zijlstra.gh-104372: On Linux where
subprocess
can use thevfork()
syscall for faster spawning, prevent the parent process from blocking other threads by dropping the GIL while it waits for the vfork'ed child processexec()
outcome. This prevents spawning a binary from a slow filesystem from blocking the rest of the application.gh-99108: We now release the GIL around built-in
hashlib
computations of reasonable size for the SHA families and MD5 hash functions, matching what our OpenSSL backed hash computations already does.gh-104399: Prepare the
_tkinter
module for building with Tcl 9.0 and future libtommath by replacing usage of deprecated functionsmp_to_unsigned_bin_n()
andmp_unsigned_bin_size()
when necessary.gh-102024: Reduce calls of
_idle_semaphore.release()
inconcurrent.futures.thread._worker()
.
Documentation¶
gh-89455: Add missing documentation for the
max_group_depth
andmax_group_width
parameters and theexceptions
attribute of thetraceback.TracebackException
class.gh-89412: Add missing documentation for the
end_lineno
andend_offset
attributes of thetraceback.TracebackException
class.gh-104943: Remove mentions of old Python versions in
typing.NamedTuple
.
Build¶
Windows¶
gh-105146: Updated the links at the end of the installer to point to Discourse rather than the mailing lists.
gh-103646: When installed from the Microsoft Store,
pip
no longer defaults to per-user installs. However, as the install directory is unwritable, it should automatically decide to do a per-user install anyway. This should resolve issues whenpip
is passed an option that conflicts with--user
.gh-88745: Improve performance of
shutil.copy2()
by using the operating system'sCopyFile2
function. This may result in subtle changes to metadata copied along with some files, bringing them in line with normal OS behavior.gh-104820: Fixes
stat()
and related functions on file systems that do not support file ID requests. This includes FAT32 and exFAT.gh-104803: Add
os.path.isdevdrive()
to detect whether a path is on a Windows Dev Drive. ReturnsFalse
on platforms that do not support Dev Drive, and is absent on non-Windows platforms.
macOS¶
gh-103142: Update macOS installer to use OpenSSL 1.1.1u.
IDLE¶
gh-104719: Remove IDLE's modification of tokenize.tabsize and test other uses of tokenize data and methods.
C API¶
gh-105115:
PyTypeObject.tp_bases
(andtp_mro
) for builtin static types are now shared by all interpreters, whereas in 3.12-beta1 they were stored onPyInterpreterState
. Also note that now the tuples are immortal objects.gh-105071: Add
PyUnstable_Exc_PrepReraiseStar
to the unstable C api to expose the implementation ofexcept*
.gh-104668: Don't call
PyOS_InputHook
orPyOS_ReadlineFunctionPointer
in subinterpreters, since it's generally difficult to avoid using global state in their registered callbacks. This also avoids situations where extensions may find themselves running in a subinterpreter they don't support (or haven't yet been loaded in).
Python 3.12.0 beta 1¶
Release date: 2023-05-22
Security¶
gh-99889: Fixed a security in flaw in
uu.decode()
that could allow for directory traversal based on the input if noout_file
was specified.gh-104049: Do not expose the local on-disk location in directory indexes produced by
http.client.SimpleHTTPRequestHandler
.gh-99108: Upgrade built-in
hashlib
SHA3 implementation to a verified implementation from theHACL*
project. Used when OpenSSL is not present or lacks SHA3.gh-102153:
urllib.parse.urlsplit()
now strips leading C0 control and space characters following the specification for URLs defined by WHATWG in response to CVE-2023-24329. Patch by Illia Volochii.
Core and Builtins¶
gh-102856: Implement PEP 701 changes in the
tokenize
module. Patch by Marta Gómez Macías and Pablo Galindo Salgadogh-104615: Fix wrong ordering of assignments in code like
a, a = x, y
. Contributed by Carl Meyer.gh-104572: Improve syntax error message for invalid constructs in PEP 695 contexts and in annotations when
from __future__ import annotations
is active.gh-104482: Fix three error handling bugs in ast.c's validation of pattern matching statements.
gh-102818: Do not add a frame to the traceback in the
sys.setprofile
andsys.settrace
trampoline functions. This ensures that frames are not duplicated if an exception is raised in the callback function, and ensures that frames are not omitted if a C callback is used and that does not add the frame.gh-104405: Fix an issue where some bytecode instructions could ignore PEP 523 when "inlining" calls.
gh-103082: Change behavior of
sys.monitoring.events.LINE
events insys.monitoring
: Line events now occur when a new line is reached dynamically, instead of using a static approximation, as before. This makes the behavior very similar to that of "line" events insys.settrace
. This should ease porting of tools from 3.11 to 3.12.gh-104263: Fix
float("nan")
to produce a quiet NaN on platforms (like MIPS) where the meaning of the signalling / quiet bit is inverted from its usual meaning. Also introduce a new macroPy_INFINITY
matching C99'sINFINITY
, and refactor internals to rely on C99'sNAN
andINFINITY
macros instead of hard-coding bit patterns for infinities and NaNs. Thanks Sebastian Berg.gh-99113: Multi-phase init extension modules may now indicate that they support running in subinterpreters that have their own GIL. This is done by using
Py_MOD_PER_INTERPRETER_GIL_SUPPORTED
as the value for thePy_mod_multiple_interpreters
module def slot. Otherwise the module, by default, cannot be imported in such subinterpreters. (This does not affect the main interpreter or subinterpreters that do not have their own GIL.) In addition to the isolation that multi-phase init already normally requires, support for per-interpreter GIL involves one additional constraint: thread-safety. If the module has external (linked) dependencies and those libraries have any state that isn't thread-safe then the module must do the additional work to add thread-safety. This should be an uncommon case.gh-99113: The GIL is now (optionally) per-interpreter. This is the fundamental change for PEP 684. This is all made possible by virtue of the isolated state of each interpreter in the process. The behavior of the main interpreter remains unchanged. Likewise, interpreters created using
Py_NewInterpreter()
are not affected. To get an interpreter with its own GIL, callPy_NewInterpreterFromConfig()
.gh-104108: Multi-phase init extension modules may now indicate whether or not they actually support multiple interpreters. By default such modules are expected to support use in multiple interpreters. In the uncommon case that one does not, it may use the new
Py_mod_multiple_interpreters
module def slot. A value of0
means the module does not support them.1
means it does. The default is1
.gh-104142: Fix an issue where
list
ortuple
repetition could fail to respect PEP 683.gh-104078: Improve the performance of
PyObject_HasAttrString()
gh-104066: Improve the performance of
hasattr()
for module objects with a missing attribute.gh-104028: Reduce object creation while calling callback function from gc. Patch by Donghee Na.
gh-104018: Disallow the "z" format specifier in %-format of bytes objects.
gh-102213: Fix performance loss when accessing an object's attributes with
__getattr__
defined.gh-103895: Improve handling of edge cases in showing
Exception.__notes__
. Ensures that the messages always end with a newline and that string/bytes are not exploded over multiple lines. Patch by Carey Metcalfe.gh-103907: Don't modify the refcounts of known immortal objects (
True
,False
, andNone
) in the main interpreter loop.gh-103899: Provide a helpful hint in the
TypeError
message when accidentally calling a module object that has a callable attribute of the same name (such asdis.dis()
ordatetime.datetime
).gh-103845: Remove both line and instruction instrumentation before adding new ones for monitoring, to avoid newly added instrumentation being removed immediately.
gh-103763: Implement PEP 695, adding syntactic support for generic classes, generic functions, and type aliases.
A new
type X = ...
syntax is added for type aliases, which resolves at runtime to an instance of the new classtyping.TypeAliasType
. The value is lazily evaluated and is accessible through the.__value__
attribute. This is implemented as a new AST nodeast.TypeAlias
.New syntax (
class X[T]: ...
,def func[T](): ...
) is added for defining generic functions and classes. This is implemented as a newtype_params
attribute on the AST nodes for classes and functions. This node holds instances of the new AST classesast.TypeVar
,ast.ParamSpec
, andast.TypeVarTuple
.typing.TypeVar
,typing.ParamSpec
,typing.ParamSpecArgs
,typing.ParamSpecKwargs
,typing.TypeVarTuple
, andtyping.Generic
are now implemented in C rather than Python.There are new bytecode instructions
LOAD_LOCALS
,LOAD_CLASSDICT_OR_GLOBAL
, andLOAD_CLASSDICT_OR_DEREF
to support correct resolution of names in class namespaces.Patch by Eric Traut, Larry Hastings, and Jelle Zijlstra.
gh-103801: Adds three minor linting fixes to the wasm module caught that were caught by ruff.
gh-103793: Optimized asyncio Task creation by deferring expensive string formatting (task name generation) from Task creation to the first time
get_name
is called. This makes asyncio benchmarks up to 5% faster.gh-102310: Change the error range for invalid bytes literals.
gh-103590: Do not wrap a single exception raised from a
try-except*
construct in anExceptionGroup
.gh-103650: Change the perf map format to remove the '0x' prefix from the addresses
gh-102856: Implement the required C tokenizer changes for PEP 701. Patch by Pablo Galindo Salgado, Lysandros Nikolaou, Batuhan Taskaya, Marta Gómez Macías and sunmy2019.
gh-100530: Clarify the error message raised when the called part of a class pattern isn't actually a class.
gh-101517: Fix bug in line numbers of instructions emitted for
except*
.gh-103492: Clarify
SyntaxWarning
with literalis
comparison by specifying which literal is problematic, since comparisons usingis
with e.g. None and bool literals are idiomatic.gh-87729: Add
LOAD_SUPER_ATTR
(and a specialization forsuper().method()
) to speed upsuper().method()
andsuper().attr
. This makessuper().method()
roughly 2.3x faster and brings it within 20% of the performance of a simple method call. Patch by Vladimir Matveev and Carl Meyer.gh-103488: Change the internal offset distinguishing yield and return target addresses, so that the instruction pointer is correct for exception handling and other stack unwinding.
gh-82012: The bitwise inversion operator (
~
) on bool is deprecated. It returns the bitwise inversion of the underlyingint
representation such thatbool(~True) == True
, which can be confusing. Usenot
for logical negation of bools. In the rare case that you really need the bitwise inversion of the underlyingint
, convert to int explicitly~int(x)
.gh-77757: Exceptions raised in a typeobject's
__set_name__
method are no longer wrapped by aRuntimeError
. Context information is added to the exception as a PEP 678 note.gh-103333:
AttributeError
now retains thename
attribute when pickled and unpickled.gh-103242: Migrate
set_ecdh_curve()
method not to use deprecated OpenSSL APIs. Patch by Donghee Na.gh-103323: We've replaced our use of
_PyRuntime.tstate_current
with a thread-local variable. This is a fairly low-level implementation detail, and there should be no change in behavior.gh-84436: The implementation of PEP-683 which adds Immortal Objects by using a fixed reference count that skips reference counting to make objects truly immutable.
gh-102700: Allow built-in modules to be submodules. This allows submodules to be statically linked into a CPython binary.
gh-103082: Implement PEP 669 Low Impact Monitoring for CPython.
gh-88691: Reduce the number of inline
CACHE
entries forCALL
.gh-102500: Make the buffer protocol accessible in Python code using the new
__buffer__
and__release_buffer__
magic methods. See PEP 688 for details. Patch by Jelle Zijlstra.gh-97933: PEP 709: inline list, dict and set comprehensions to improve performance and reduce bytecode size.
gh-99184: Bypass instance attribute access of
__name__
inrepr
ofweakref.ref
.gh-98003: Complex function calls are now faster and consume no C stack space.
bpo-39610:
len()
for 0-dimensionalmemoryview`
objects (such asmemoryview(ctypes.c_uint8(42))
) now raises aTypeError
. Previously this returned1
, which was not consistent withmem_0d[0]
raising anIndexError`
.bpo-31821: Fix
pause_reading()
to work when called fromconnection_made()
inasyncio
.
Library¶
gh-104600:
functools.update_wrapper()
now sets the__type_params__
attribute (added by PEP 695).gh-104340: When an
asyncio
pipe protocol loses its connection due to an error, and the caller doesn't awaitwait_closed()
on the correspondingStreamWriter
, don't log a warning about an exception that was never retrieved. After all, according to theStreamWriter.close()
docs, thewait_closed()
call is optional ("not mandatory").gh-104555: Fix issue where an
issubclass()
check comparing a classX
against aruntime-checkable protocol
Y
with non-callable members would not causeTypeError
to be raised if anisinstance()
call had previously been made comparing an instance ofX
toY
. This issue was present in edge cases on Python 3.11, but became more prominent in 3.12 due to some unrelated changes that were made to runtime-checkable protocols. Patch by Alex Waygood.gh-104372: Refactored the
_posixsubprocess
internals to avoid Python C API usage between fork and exec when markingpass_fds=
file descriptors inheritable.gh-104484: Added case_sensitive argument to
pathlib.PurePath.match()
gh-75367: Fix data descriptor detection in
inspect.getattr_static()
.gh-104536: Fix a race condition in the internal
multiprocessing.process
cleanup logic that could manifest as an unintendedAttributeError
when callingprocess.close()
.gh-103857: Update datetime deprecations' stracktrace to point to the calling line
gh-101520: Move the core functionality of the
tracemalloc
module in thePython/
folder, leaving just the module wrapper inModules/
.gh-104392: Remove undocumented and unused
_paramspec_tvars
attribute from some classes intyping
.gh-102613: Fix issue where
pathlib.Path.glob()
raisedRecursionError
when walking deep directory trees.gh-103000: Improve performance of
dataclasses.asdict()
for the common case where dict_factory isdict
. Patch by David C Ellis.gh-104301: Allow leading whitespace in disambiguated statements in
pdb
.gh-104139: Teach
urllib.parse.unsplit()
to retain the"//"
when assemblingitms-services://?action=generate-bugs
style Apple Platform Deployment URLs.gh-104307:
socket.getnameinfo()
now releases the GIL while contacting the DNS servergh-104310: Users may now use
importlib.util.allowing_all_extensions()
(a context manager) to temporarily disable the strict compatibility checks for importing extension modules in subinterpreters.gh-87695: Fix issue where
pathlib.Path.glob()
raisedOSError
when it encountered a symlink to an overly long path.gh-104265: Prevent possible crash by disallowing instantiation of the
_csv.Reader
and_csv.Writer
types. The regression was introduced in 3.10.0a4 with PR 23224 (bpo-14935). Patch by Radislav Chugunov.gh-102613: Improve performance of
pathlib.Path.glob()
when expanding recursive wildcards ("**
") by merging adjacent wildcards and de-duplicating results only when necessary.gh-65772: Remove unneeded comments and code in turtle.py.
gh-90208: Fixed issue where
pathlib.Path.glob()
returned incomplete results when it encountered aPermissionError
. This method now suppresses allOSError
exceptions, except those raised from callingis_dir()
on the top-level path.gh-104144: Optimize
asyncio.TaskGroup
when usingasyncio.eager_task_factory()
. Skip scheduling a done callback if a TaskGroup task completes eagerly.gh-104144: Optimize
asyncio.gather()
when usingasyncio.eager_task_factory()
to complete eagerly if all fututres completed eagerly. Avoid scheduling done callbacks for futures that complete eagerly.gh-104114: Fix issue where
pathlib.Path.glob()
returns paths using the case of non-wildcard segments for corresponding path segments, rather than the real filesystem case.gh-104104: Improve performance of
pathlib.Path.glob()
by usingre.IGNORECASE
to implement case-insensitive matching.gh-104102: Improve performance of
pathlib.Path.glob()
when evaluating patterns that contain'../'
segments.gh-103822: Update the return type of
weekday
to the newly added Day attributegh-103629: Update the
repr
oftyping.Unpack
according to PEP 692.gh-103963: Make
dis
display the names of the args forCALL_INTRINSIC_*
.gh-104035: Do not ignore user-defined
__getstate__
and__setstate__
methods for slotted frozen dataclasses.gh-103987: In
mmap
, fix several bugs that could lead to access to memory-mapped files after they have been invalidated.gh-88773: Added
turtle.teleport()
to theturtle
module to move a turtle to a new point without tracing a line, visible or invisible. Patch by Liam Gersten.gh-103935: Use
io.open_code()
for files to be executed instead of rawopen()
gh-68968: Fixed garbled output of
assertEqual()
when an input lacks final newline.gh-100370: Fix potential
OverflowError
insqlite3.Connection.blobopen()
for 32-bit builds. Patch by Erlend E. Aasland.gh-102628: Substitute CTRL-D with CTRL-Z in
sqlite3
CLI banner when running on Windows.gh-103636: Module-level attributes
January
andFebruary
are deprecated fromcalendar
.gh-103583: Isolate
_multibytecodec
and codecs extension modules. Patches by Erlend E. Aasland.gh-103848: Add checks to ensure that
[
bracketed]
hosts found byurllib.parse.urlsplit()
are of IPv6 or IPvFuture format.gh-103872: Update the bundled copy of pip to version 23.1.2.
gh-74940: The C.UTF-8 locale is no longer converted to en_US.UTF-8, enabling the use of UTF-8 encoding on systems which have no locales installed.
gh-103861: Fix
zipfile.Zipfile
creating invalid zip files whenforce_zip64
was used to add files to them. Patch by Carey Metcalfe.gh-103857: Deprecated
datetime.datetime.utcnow()
anddatetime.datetime.utcfromtimestamp()
. (Patch by Paul Ganssle)gh-103839: Avoid compilation error due to tommath.h not being found when building Tkinter against Tcl 8.7 built with bundled libtommath.
gh-103791:
contextlib.suppress
now supports suppressing exceptions raised as part of anExceptionGroup
. If other exceptions exist on the group, they are re-raised in a group that does not contain the suppressed exceptions.gh-90750: Use
datetime.datetime.fromisocalendar()
in the implementation ofdatetime.datetime.strptime()
, which should now accept only valid ISO dates. (Patch by Paul Ganssle)gh-103685: Prepare
tkinter.Menu.index()
for Tk 8.7 so that it does not raiseTclError: expected integer but got ""
when it should returnNone
.gh-81403:
urllib.request.CacheFTPHandler
no longer raisesURLError
if a cached FTP instance is reused. ftplib's endtransfer method calls voidresp to drain the connection to handle FTP instance reuse properly.gh-103699: Add
__orig_bases__
to non-generic TypedDicts, call-based TypedDicts, and call-based NamedTuples. Other TypedDicts and NamedTuples already had the attribute.gh-92248: Deprecate
type
,choices
, andmetavar
parameters ofargparse.BooleanOptionalAction
.gh-89415: Add
socket
constants for source-specific multicast. Patch by Reese Hyde.gh-103673:
socketserver
gainsForkingUnixStreamServer
andForkingUnixDatagramServer
classes. Patch by Jay Berry.gh-103636: Added Enum for months and days in the calendar module.
gh-84976: Create a new
Lib/_pydatetime.py
file that defines the Python version of thedatetime
module, and makedatetime
import the contents of the new library only if the C implementation is missing. Currently, the full Python implementation is defined and then deleted if the C implementation is not available, slowing downimport datetime
unnecessarily.gh-103596: Attributes/methods are no longer shadowed by same-named enum members, although they may be shadowed by enum.property's.
gh-103584: Updated
importlib.metadata
with changes fromimportlib_metadata
5.2 through 6.5.0, including: Supportinstalled-files.txt
forDistribution.files
when present.PackageMetadata
now stipulates an additionalget
method allowing for easy querying of metadata keys that may not be present.packages_distributions
now honors packages and modules with Python modules that not.py
sources (e.g..pyc
,.so
). Expand protocol forPackageMetadata.get_all
to match the upstream implementation ofemail.message.Message.get_all
in python/typeshed#9620. Deprecated use ofDistribution
without defining abstract methods. Deprecated expectation thatPackageMetadata.__getitem__
will returnNone
for missing keys. In the future, it will raise aKeyError
.gh-103578: Fixed a bug where
pdb
crashes when reading source file with different encoding by replacingio.open()
withio.open_code()
. The new method would also call into the hook set byPyFile_SetOpenCodeHook()
.gh-103556: Now creating
inspect.Signature
objects with positional-only parameter with a default followed by a positional-or-keyword parameter without one is impossible.gh-103559: Update the bundled copy of pip to version 23.1.1.
gh-103548: Improve performance of
pathlib.Path.absolute()
andcwd()
by joining paths only when necessary. Also improve performance ofpathlib.PurePath.is_absolute()
on Posix by skipping path parsing and normalization.gh-103538: Remove
_tkinter
module code guarded by definition of theTK_AQUA
macro which was only needed for Tk 8.4.7 or earlier and was never actually defined by any build system or documented for manual use.gh-103525: Fix misleading exception message when mixed
str
andbytes
arguments are supplied topathlib.PurePath
andPath
.gh-103489: Add
getconfig()
andsetconfig()
toConnection
to make configuration changes to a database connection. Patch by Erlend E. Aasland.gh-103365: Set default Flag boundary to
STRICT
and fix bitwise operations.gh-103472: Avoid a potential
ResourceWarning
inhttp.client.HTTPConnection
by closing the proxy / tunnel's CONNECT response explicitly.gh-103462: Fixed an issue with using
writelines()
inasyncio
to send very large payloads that exceed the amount of data that can be written in one call tosocket.socket.send()
orsocket.socket.sendmsg()
, resulting in the remaining buffer being left unwritten.gh-103449: Fix a bug in doc string generation in
dataclasses.dataclass()
.gh-103092: Isolate
_collections
(apply PEP 687). Patch by Erlend E. Aasland.gh-103357: Added support for
logging.Formatter
defaults
parameter tologging.config.dictConfig()
andlogging.config.fileConfig()
. Patch by Bar Harel.gh-74690: The performance of
isinstance()
checks againstruntime-checkable protocols
has been considerably improved for protocols that only have a few members. To achieve this improvement, several internal implementation details of thetyping
module have been refactored, includingtyping._ProtocolMeta.__instancecheck__
,typing._is_callable_members_only
, andtyping._get_protocol_attrs
. Patches by Alex Waygood.gh-74690: The members of a runtime-checkable protocol are now considered "frozen" at runtime as soon as the class has been created. See "What's new in Python 3.12" for more details.
gh-103256: Fixed a bug that caused
hmac
to raise an exception when the requested hash algorithm was not available in OpenSSL despite being available separately as part ofhashlib
itself. It now falls back properly to the built-in. This could happen when, for example, your OpenSSL does not include SHA3 support and you want to computehmac.digest(b'K', b'M', 'sha3_256')
.gh-103285: Improve performance of
ast.get_source_segment()
.gh-103225: Fix a bug in
pdb
when displaying line numbers of module-level source code.gh-93910: Remove deprecation of enum
memmber.member
access.gh-102978: Fixes
unittest.mock.patch()
not enforcing function signatures for methods decorated with@classmethod
or@staticmethod
when patch is called withautospec=True
.gh-103092: Isolate
_socket
(apply PEP 687). Patch by Erlend E. Aasland.gh-100479: Add
pathlib.PurePath.with_segments()
, which creates a path object from arguments. This method is called whenever a derivative path is created, such as frompathlib.PurePath.parent
. Subclasses may override this method to share information between path objects.gh-103220: Fix issue where
os.path.join()
added a slash when joining onto an incomplete UNC drive with a trailing slash on Windows.gh-103204: Fixes
http.server
accepting HTTP requests with HTTP version numbers preceded by '+', or '-', or with digit-separating '_' characters. The length of the version numbers is also constrained.gh-75586: Fix various Windows-specific issues with
shutil.which
.gh-103193: Improve performance of
inspect.getattr_static()
. Patch by Alex Waygood.gh-103176:
sys._current_exceptions()
now returns a mapping from thread-id to an exception instance, rather than to a(typ, exc, tb)
tuple.gh-103015: Add entrypoint keyword-only parameter to
sqlite3.Connection.load_extension()
, for overriding the SQLite extension entry point. Patch by Erlend E. Aasland.gh-103000: Improve performance of
dataclasses.astuple()
anddataclasses.asdict()
in cases where the contents are common Python types.gh-102953: The extraction methods in
tarfile
, andshutil.unpack_archive()
, have a new a filter argument that allows limiting tar features than may be surprising or dangerous, such as creating files outside the destination directory. See 解压缩过滤器 for details.gh-97696: Implemented an eager task factory in asyncio. When used as a task factory on an event loop, it performs eager execution of coroutines. Coroutines that are able to complete synchronously (e.g. return or raise without blocking) are returned immediately as a finished task, and the task is never scheduled to the event loop. If the coroutine blocks, the (pending) task is scheduled and returned.
gh-81079: Add case_sensitive keyword-only argument to
pathlib.Path.glob()
andrglob()
.gh-101819: Isolate the
io
extension module by applying PEP 687. Patch by Kumar Aditya, Victor Stinner, and Erlend E. Aasland.gh-91896: Deprecate
collections.abc.ByteString
gh-101362: Speed up
pathlib.Path
construction by omitting the path anchor from the internal list of path parts.gh-102114: Functions in the
dis
module that accept a source code string as argument now print a more concise traceback when the string contains a syntax or indentation error.gh-62432: The
unittest
runner will now exit with status code 5 if no tests were run. It is common for test runner misconfiguration to fail to find any tests, this should be an error.gh-78079: Fix incorrect normalization of UNC device path roots, and partial UNC share path roots, in
pathlib.PurePath
. Pathlib no longer appends a trailing slash to such paths.gh-85984: Add
tty.cfmakeraw()
andtty.cfmakecbreak()
totty
and modernize, the behavior oftty.setraw()
andtty.setcbreak()
to use POSIX.1-2017 Chapter 11 "General Terminal Interface" flag masks by default.gh-101688: Implement
types.get_original_bases()
to provide further introspection for types.gh-101640:
argparse.ArgumentParser
now catches errors when writing messages, such as whensys.stderr
isNone
. Patch by Oleg Iarygin.gh-83861: Fix datetime.astimezone method return value when invoked on a naive datetime instance that represents local time falling in a timezone transition gap. PEP 495 requires that instances with fold=1 produce earlier times than those with fold=0 in this case.
gh-89550: Decrease execution time of some
gzip
file writes by 15% by adding more appropriate buffering.gh-95299: Remove the bundled setuptools wheel from
ensurepip
, and stop installing setuptools in environments created byvenv
.gh-99353: Respect the
http.client.HTTPConnection
.debuglevel
flag inurllib.request.AbstractHTTPHandler
when its constructor parameterdebuglevel
is not set. And do the same for*HTTPS*
.gh-98040: Remove the long-deprecated
imp
module.gh-97850: Deprecate
pkgutil.find_loader()
andpkgutil.get_loader()
in favor ofimportlib.util.find_spec()
.gh-94473: Flatten arguments in
tkinter.Canvas.coords()
. It now accepts not onlyx1, y1, x2, y2, ...
and[x1, y1, x2, y2, ...]
, but also(x1, y1), (x2, y2), ...
and[(x1, y1), (x2, y2), ...]
.gh-98040: Remove more deprecated importlib APIs:
find_loader()
,find_module()
,importlib.abc.Finder
,pkgutil.ImpImporter
,pkgutil.ImpLoader
.gh-96522: Fix potential deadlock in pty.spawn()
gh-96534: Support divert(4) added in FreeBSD 14.
gh-87474: Fix potential file descriptor leaks in
subprocess.Popen
.gh-94906: Support multiple steps in
math.nextafter()
. Patch by Shantanu Jain and Matthias Gorgens.gh-51574: Make
tempfile.mkdtemp()
return absolute paths when its dir parameter is relative.gh-94518: Convert private
_posixsubprocess.fork_exec()
to use Argument Clinic.gh-92184: When creating zip files using
zipfile
,os.altsep
, if notNone
, will always be treated as a path separator even when it is not/
. Patch by Carey Metcalfe.bpo-46797: Deprecation warnings are now emitted for
ast.Num
,ast.Bytes
,ast.Str
,ast.NameConstant
andast.Ellipsis
. These have been documented as deprecated since Python 3.8, and will be removed in Python 3.14.bpo-44844: Enables
webbrowser
to detect and launch Microsoft Edge browser.bpo-45606: Fixed the bug in
pathlib.Path.glob()
-- previously a dangling symlink would not be found by this method when the pattern is an exact match, but would be found when the pattern contains a wildcard or the recursive wildcard (**
). With this change, a dangling symlink will be found in both cases.bpo-23041: Add
QUOTE_STRINGS
andQUOTE_NOTNULL
to the suite ofcsv
module quoting styles.bpo-24964: Added
http.client.HTTPConnection.get_proxy_response_headers()
that provides access to the HTTP headers on a proxy server response to theCONNECT
request.bpo-17258:
multiprocessing
now supports stronger HMAC algorithms for inter-process connection authentication rather than only HMAC-MD5.bpo-39744: Make
asyncio.subprocess.Process.communicate()
close the subprocess's stdin even when called withinput=None
.bpo-22708: http.client CONNECT method tunnel improvements: Use HTTP 1.1 protocol; send a matching Host: header with CONNECT, if one is not provided; convert IDN domain names to Punycode. Patch by Michael Handler.
Documentation¶
gh-67056: Document that the effect of registering or unregistering an
atexit
cleanup function from within a registered cleanup function is undefined.gh-103629: Mention the new way of typing
**kwargs
withUnpack
andTypedDict
introduced in PEP 692.gh-48241: Clarifying documentation about the url parameter to urllib.request.urlopen and urllib.request.Request needing to be encoded properly.
gh-86094: Add support for Unicode Path Extra Field in ZipFile. Patch by Yeojin Kim and Andrea Giudiceandrea
gh-99202: Fix extension type from documentation for compiling in C++20 mode
Tests¶
gh-104494: Update
test_pack_configure_in
andtest_place_configure_in
for changes to error message formatting in Tk 8.7.gh-104461: Run test_configure_screen on X11 only, since the
DISPLAY
environment variable and-screen
option for toplevels are not useful on Tk for Win32 or Aqua.gh-86275: Added property-based tests to the
zoneinfo
tests, along with stubs for thehypothesis
interface. (Patch by Paul Ganssle)gh-103329: Regression tests for the behaviour of
unittest.mock.PropertyMock
were added.gh-102795: fix use of poll in test_epoll's test_control_and_wait
gh-75729: Fix the
os.spawn*
tests failing on Windows when the working directory or interpreter path contains spaces.
Build¶
gh-101282: BOLT optimization is now applied to the libpython shared library if building a shared library. BOLT instrumentation and application settings can now be influenced via the
BOLT_INSTRUMENT_FLAGS
andBOLT_APPLY_FLAGS
configure variables.gh-99017:
PYTHON_FOR_REGEN
now require Python 3.10 or newer.gh-104490: Define
.PHONY
/ virtual make targets consistently and properly.gh-104106: Add gcc fallback of mkfifoat/mknodat for macOS. Patch by Donghee Na.
gh-103532: The
TKINTER_PROTECT_LOADTK
macro is no longer defined or used in the_tkinter
module. It was previously only defined when building against Tk 8.4.13 and older, but Tk older than 8.5.12 has been unsupported since gh-91152.gh-99069: Extended workaround defining
static_assert
when missing from the libc headers to all clang and gcc builds. In particular, this fixes building on macOS <= 10.10.gh-100220: Changed the default value of the
SHELL
Makefile variable from/bin/sh
to/bin/sh -e
to ensure that complex recipes correctly fail after an error. Previously,make install
could fail to install some files and yet return a successful result.gh-90656: Add platform triplets for 64-bit LoongArch:
loongarch64-linux-gnusf
loongarch64-linux-gnuf32
loongarch64-linux-gnu
Patch by Zhang Na.
Windows¶
gh-104623: Update Windows installer to use SQLite 3.42.0.
gh-82814: Fix a potential
[Errno 13] Permission denied
when usingshutil.copystat()
within Windows Subsystem for Linux (WSL) on a mounted filesystem by addingerrno.EACCES
to the list of ignored errors within the internal implementation.gh-103088: Fix virtual environment
activate
script having incorrect line endings for Cygwin.gh-103088: Fixes venvs not working in bash on Windows across different disks
gh-102997: Update Windows installer to use SQLite 3.41.2.
gh-88013: Fixed a bug where
TypeError
was raised when callingntpath.realpath()
with a bytes parameter in some cases.
macOS¶
gh-99834: Update macOS installer to Tcl/Tk 8.6.13.
gh-104623: Update macOS installer to SQLite 3.42.0.
gh-103545: Add
os.PRIO_DARWIN_THREAD
,os.PRIO_DARWIN_PROCESS
,os.PRIO_DARWIN_BG
andos.PRIO_DARWIN_NONUI
. These can be used withos.setpriority
to run the process at a lower priority and make use of the efficiency cores on Apple Silicon systems.gh-104180: Support reading SOCKS proxy configuration from macOS System Configuration. Patch by Sam Schott.
gh-60436: update curses textbox to additionally handle backspace using the
curses.ascii.DEL
key press.gh-102997: Update macOS installer to SQLite 3.41.2.
IDLE¶
Tools/Demos¶
C API¶
gh-101291: Added unstable C API for extracting the value of "compact" integers:
PyUnstable_Long_IsCompact()
andPyUnstable_Long_CompactValue()
.gh-104109: We've added
Py_NewInterpreterFromConfig()
andPyInterpreterConfig
to the public C-API (but not the stable ABI; not yet at least). The new function may be used to create a new interpreter with various features configured. The function was added to support PEP 684 (per-interpreter GIL).gh-103968:
PyType_FromSpec()
and its variants now allow creating classes whose metaclass overridestp_new
. Thetp_new
is ignored. This behavior is deprecated and will be disallowed in 3.14+. The newPyType_FromMetaclass()
already disallows it.gh-103743: Add
PyUnstable_Object_GC_NewWithExtraData()
function that can be used to allocate additional memory after an object for data not managed by Python.gh-103295: Introduced
PyUnstable_WritePerfMapEntry()
,PyUnstable_PerfMapState_Init()
andPyUnstable_PerfMapState_Fini()
. These allow extension modules (JIT compilers in particular) to write to perf-map files in a thread safe manner. The Python 对 Linux perf 性能分析器的支持 also uses these APIs to write entries in the perf-map file.gh-103509: Added C API for extending types whose instance memory layout is opaque:
PyType_Spec.basicsize
can now be zero or negative,PyObject_GetTypeData()
can be used to get subclass-specific data, andPy_TPFLAGS_ITEMS_AT_END
can be used to safely extend variable-size objects. See PEP 697 for details.gh-103091: Add a new C-API function to eagerly assign a version tag to a PyTypeObject:
PyUnstable_Type_AssignVersionTag()
.gh-101408:
PyObject_GC_Resize()
should calculate preheader size if needed. Patch by Donghee Na.gh-98836: Add support of more formatting options (left aligning, octals, uppercase hexadecimals,
intmax_t
,ptrdiff_t
,wchar_t
C strings, variable width and precision) inPyUnicode_FromFormat()
andPyUnicode_FromFormatV()
.gh-96803: Add unstable C-API functions to get the code object, lasti and line number from the internal
_PyInterpreterFrame
in the limited API. The functions are:PyCodeObject * PyUnstable_InterpreterFrame_GetCode(struct _PyInterpreterFrame *frame)
int PyUnstable_InterpreterFrame_GetLasti(struct _PyInterpreterFrame *frame)
int PyUnstable_InterpreterFrame_GetLine(struct _PyInterpreterFrame *frame)
Python 3.12.0 alpha 7¶
Release date: 2023-04-04
Core and Builtins¶
gh-102192: Deprecated
_PyErr_ChainExceptions
in favour of_PyErr_ChainExceptions1
.gh-89987: Reduce the number of inline
CACHE
entries forBINARY_SUBSCR
.gh-102859: Removed
JUMP_IF_FALSE_OR_POP
andJUMP_IF_TRUE_OR_POP
instructions.gh-101975: Fixed
stacktop
value on tracing entries to avoid corruption on garbage collection.gh-102778: Add
sys.last_exc
and deprecatesys.last_type
,sys.last_value
andsys.last_traceback
, which hold the same information in its legacy form.gh-100982: Replace all occurrences of
COMPARE_AND_BRANCH
withCOMPARE_OP
.gh-102701: Fix overflow when creating very large dict.
gh-102755: Add
PyErr_DisplayException()
which takes just an exception instance, to replace the legacyPyErr_Display()
which takes the(typ, exc, tb)
triplet.gh-102594: Add note to exception raised in
PyErr_SetObject
when normalization fails.gh-90997: Shrink the number of inline
CACHE
entries used byLOAD_GLOBAL
.gh-102491: Improve import time of
platform
by removing IronPython version parsing. The IronPython version parsing was not functional (see https://github.com/IronLanguages/ironpython3/issues/1667).gh-101291: Rearrage bits in first field (after header) of PyLongObject. * Bits 0 and 1: 1 - sign. I.e. 0 for positive numbers, 1 for zero and 2 for negative numbers. * Bit 2 reserved (probably for the immortal bit) * Bits 3+ the unsigned size.
This makes a few operations slightly more efficient, and will enable a more compact and faster 2s-complement representation of most ints in future.
gh-102397: Fix segfault from race condition in signal handling during garbage collection. Patch by Kumar Aditya.
gh-102406:
codecs
encoding/decoding errors now get the context information (which operation and which codecs) attached as PEP 678 notes instead of through chaining a new instance of the exception.gh-102281: Fix potential nullptr dereference and use of uninitialized memory in fileutils. Patch by Max Bachmann.
gh-102300: Reuse operands with refcount of 1 in float specializations of BINARY_OP.
gh-102213: Fix performance loss when accessing an object's attributes with
__getattr__
defined.gh-102255: Improve build support for the Xbox. Patch by Max Bachmann.
gh-102027: Fix SSE2 and SSE3 detection in
_blake2
internal module. Patch by Max Bachmann.gh-101865: Deprecate
co_lnotab
in code objects, schedule it for removal in Python 3.14bpo-1635741: Adapt
_pickle
to PEP 687. Patch by Mohamed Koubaa and Erlend Aasland.
Library¶
gh-103085: Pure python
locale.getencoding()
will not warn deprecation.gh-103068: It's no longer possible to register conditional breakpoints in
Pdb
that raiseSyntaxError
. Patch by Tian Gao.gh-102549: Don't ignore exceptions in member type creation.
gh-103056: Ensure final
_generate_next_value_
is astaticmethod
.gh-103046: Display current line label correctly in
dis
whenshow_caches
is False andlasti
points to a CACHE entry.gh-102433:
isinstance()
checks againstruntime-checkable protocols
now useinspect.getattr_static()
rather thanhasattr()
to lookup whether attributes exist. This means that descriptors and__getattr__()
methods are no longer unexpectedly evaluated duringisinstance()
checks against runtime-checkable protocols. However, it may also mean that some objects which used to be considered instances of a runtime-checkable protocol may no longer be considered instances of that protocol on Python 3.12+, and vice versa. Most users are unlikely to be affected by this change. Patch by Alex Waygood.gh-103023: It's no longer possible to register expressions to display in
Pdb
that raiseSyntaxError
. Patch by Tian Gao.gh-102947: Improve traceback when
dataclasses.fields()
is called on a non-dataclass. Patch by Alex Waygoodgh-102780: The
asyncio.Timeout
context manager now works reliably even when performing cleanup due to task cancellation. Previously it could raise aCancelledError
instead of anTimeoutError
in such cases.gh-102871: Remove support for obsolete browsers from
webbrowser
. Removed browsers include Grail, Mosaic, Netscape, Galeon, Skipstone, Iceape, Firebird, and Firefox versions 35 and below.gh-102839: Improve performance of
math.log()
arguments handling by removing the argument clinic.gh-102828: Add the
onexc
arg toshutil.rmtree()
, which is likeonerror
but expects an exception instance rather than an exc_info tuple. Deprecateonerror
.gh-88965: typing: Fix a bug relating to substitution in custom classes generic over a
ParamSpec
. Previously, if theParamSpec
was substituted with a parameters list that itself contained aTypeVar
, theTypeVar
in the parameters list could not be subsequently substituted. This is now fixed.Patch by Nikita Sobolev.
gh-76846: Fix issue where
__new__()
and__init__()
methods ofpathlib.PurePath
andPath
subclasses were not called in some circumstances.gh-78530:
asyncio.wait()
now accepts generators yielding tasks. Patch by Kumar Aditya.gh-102748:
asyncio.iscoroutine()
now returnsFalse
for generators asasyncio
does not support legacy generator-based coroutines. Patch by Kumar Aditya.gh-102670: Optimized fmean(), correlation(), covariance(), and linear_regression() using the new math.sumprod() function.
gh-102615: Typing: Improve the
repr
of generic aliases for classes generic over aParamSpec
. (Use square brackets to represent a parameter list.)gh-100112:
asyncio.Task.get_coro()
now always returns a coroutine when wrapping an awaitable object. Patch by Kumar Aditya.gh-102578: Speed up setting or deleting mutable attributes on non-dataclass subclasses of frozen dataclasses. Due to the implementation of
__setattr__
and__delattr__
for frozen dataclasses, this previously had a time complexity ofO(n)
. It now has a time complexity ofO(1)
.gh-102519: Add
os.listdrives()
,os.listvolumes()
andos.listmounts()
functions on Windows for enumerating drives, volumes and mount pointsgh-74468: Attribute name of the extracted
tarfile
file object now holds filename of itself rather than of the archive it is contained in. Patch by Oleg Iarygin.gh-102378: Private helper method
inspect._signature_strip_non_python_syntax
will no longer strip/
from the input string.gh-79940: Add
inspect.getasyncgenstate()
andinspect.getasyncgenlocals()
. Patch by Thomas Krennwallner.gh-102103: Add
module
argument todataclasses.make_dataclass()
and make classes produced by it pickleable.gh-102069: Fix
__weakref__
descriptor generation for custom dataclasses.gh-102038: Skip a
stat
insite
if we have already found apyvenv.cfg
gh-98886: Fix issues when defining dataclasses that have fields with specific underscore names that aren't clearly reserved by
dataclasses
.gh-101673: Fix a
pdb
bug wherell
clears the changes to local variables.gh-101313: Added -h and --help arguments to the webbrowser CLI
gh-100372:
ssl.SSLContext.load_verify_locations()
no longer incorrectly accepts some cases of trailing data when parsing DER.gh-89727: Fix pathlib.Path.walk RecursionError on deep directory trees by rewriting it using iteration instead of recursion.
gh-100131: Added an optional
delete
keyword argument totempfile.TemporaryDirectory
.gh-48330: Added
--durations
command line option, showing the N slowest test cases.unittest.TextTestRunner
andunittest.TextTestResult
constructors accept a new durations keyword argument. Subclasses should take this into account or accept**kwargs
. Addedunittest.TestResult.addDuration()
method andunittest.TestResult.collectedDurations
attribute.(Contributed by Giampaolo Rodola)
gh-98169: Fix
dataclasses.astuple()
crash whencollections.defaultdict
is present in the attributes.gh-96931: Fix incorrect results from
ssl.SSLSocket.shared_ciphers()
gh-95495: When built against OpenSSL 3.0, the
ssl
module had a bug where it reported unauthenticated EOFs (i.e. without close_notify) as a clean TLS-level EOF. It now raisesSSLEOFError
, matching the behavior in previous versions of OpenSSL. Theoptions
attribute onSSLContext
also no longer includesOP_IGNORE_UNEXPECTED_EOF
by default. This option may be set to specify the previous OpenSSL 3.0 behavior.gh-94684: Now
uuid.uuid3()
anduuid.uuid5()
functions supportbytes
objects as their name argument.gh-94440: Fix a
concurrent.futures.process
bug whereProcessPoolExecutor
shutdown could hang after a future has been quickly submitted and canceled.gh-72346: Added deprecation warning to isdst parameter of
email.utils.localtime()
.bpo-36305: Fix handling of Windows filenames that resemble drives, such as
./a:b
, inpathlib
.
Documentation¶
gh-103112: Add docstring to
http.client.HTTPResponse.read()
to fixpydoc
output.
Tests¶
Build¶
Windows¶
gh-102690: Update
webbrowser
to fall back to Microsoft Edge instead of Internet Explorer.gh-99726: Improves correctness of stat results for Windows, and uses faster API when available
Tools/Demos¶
gh-102809:
Misc/gdbinit
was removed.
C API¶
gh-102013: Add a new (unstable) C-API function for iterating over GC'able objects using a callback:
PyUnstable_VisitObjects
.
Python 3.12.0 alpha 6¶
Release date: 2023-03-07
Security¶
gh-99108: Replace builtin hashlib implementations of MD5 and SHA1 with verified ones from the HACL* project.
gh-101727: Updated the OpenSSL version used in Windows and macOS binary release builds to 1.1.1t to address CVE-2023-0286, CVE-2022-4303, and CVE-2022-4303 per the OpenSSL 2023-02-07 security advisory.
gh-99108: Replace the builtin
hashlib
implementations of SHA2-384 and SHA2-512 originally from LibTomCrypt with formally verified, side-channel resistant code from the HACL* project. The builtins remain a fallback only used when OpenSSL does not provide them.gh-101283:
subprocess.Popen
now uses a safer approach to findcmd.exe
when launching withshell=True
. Patch by Eryk Sun, based on a patch by Oleg Iarygin.
Core and Builtins¶
gh-102493: Fix regression in semantics of normalisation in
PyErr_SetObject
.gh-102416: Do not memoize incorrectly automatically generated loop rules in the parser. Patch by Pablo Galindo.
gh-102356: Fix a bug that caused a crash when deallocating deeply nested filter objects. Patch by Marta Gómez Macías.
gh-102336: Cleanup Windows 7 specific special handling. Patch by Max Bachmann.
gh-102250: Fixed a segfault occurring when the interpreter calls a
__bool__
method that raises.gh-102126: Fix deadlock at shutdown when clearing thread states if any finalizer tries to acquire the runtime head lock. Patch by Kumar Aditya.
gh-102027: Use
GetCurrentProcessId
on Windows whengetpid
is unavailable. Patch by Max Bachmann.gh-102056: Fix error handling bugs in interpreter's exception printing code, which could cause a crash on infinite recursion.
gh-100982: Restrict the scope of the
FOR_ITER_RANGE
instruction to the scope of the originalFOR_ITER
instruction, to allow instrumentation.gh-101967: Fix possible segfault in
positional_only_passed_as_keyword
function, when new list created.gh-101952: Fix possible segfault in
BUILD_SET
opcode, when new set created.gh-74895:
socket.getaddrinfo
no longer raisesOverflowError
forint
port values outside of the C long range. Out of range values are left up to the underlying string based C library API to report. Asocket.gaierror
SAI_SERVICE
may occur instead, or no error at all as not all platform C libraries generate an error.gh-101799: Add
CALL_INTRINSIC_2
and use it instead ofPREP_RERAISE_STAR
.gh-101857: Fix xattr support detection on Linux systems by widening the check to linux, not just glibc. This fixes support for musl.
gh-84783: Make the slice object hashable. Patch by Will Bradshaw and Furkan Onder.
gh-87849: Change the
SEND
instruction to leave the receiver on the stack. This allows the specialized form ofSEND
to skip the chain of C calls and jump directly to theRESUME
in the generator or coroutine.gh-101765: Fix SystemError / segmentation fault in iter
__reduce__
when internal access ofbuiltins.__dict__
keys mutates the iter object.gh-101430: Update
tracemalloc
to handle presize of object properly. Patch by Donghee Na.gh-101696: Invalidate type version tag in
_PyStaticType_Dealloc
for static types, avoiding bug where a false cache hit could crash the interpreter. Patch by Kumar Aditya.gh-101632: Adds a new
RETURN_CONST
instruction.gh-100719: Remove gi_code field from generator (and coroutine and async generator) objects as it is redundant. The frame already includes a reference to the code object.
gh-98627: When an interpreter is configured to check (and only then), importing an extension module will now fail when the extension does not support multiple interpreters (i.e. doesn't implement PEP 489 multi-phase init). This does not apply to the main interpreter, nor to subinterpreters created with
Py_NewInterpreter()
.
Library¶
gh-102302: Micro-optimise hashing of
inspect.Parameter
, reducing the time it takes to hash an instance by around 40%.gh-101979: Fix a bug where parentheses in the
metavar
argument toargparse.ArgumentParser.add_argument()
were dropped. Patch by Yeojin Kim.gh-91038:
platform.platform()
now has boolean default arguments.gh-81652: Add
mmap.MAP_ALIGNED_SUPER
FreeBSD andmmap.MAP_CONCEAL
OpenBSD constants tommap
. Patch by Yeojin Kim.gh-101961: For the binary mode,
fileinput.hookcompressed()
doesn't set theencoding
value even if the value isNone
. Patch by Gihwan Kim.gh-101936: The default value of
fp
becomesio.BytesIO
ifHTTPError
is initialized without a designatedfp
parameter. Patch by Long Vo.gh-101566: In zipfile, sync Path with zipp 3.14, including fix for extractall on the underlying zipfile after being wrapped in
Path
.gh-97930: Apply changes from importlib_resources 5.12, including fix for
MultiplexedPath
to support directories in multiple namespaces (python/importlib_resources#265).gh-101997: Upgrade pip wheel bundled with ensurepip (pip 23.0.1)
gh-99108: The built-in extension modules for
hashlib
SHA2 algorithms, used when OpenSSL does not provide them, now live in a single internal_sha2
module instead of separate_sha256
and_sha512
modules.gh-101892: Callable iterators no longer raise
SystemError
when the callable object exhausts the iterator but forgets to either return a sentinel value or raiseStopIteration
.gh-87634: Remove locking behavior from
functools.cached_property()
.gh-97786: Fix potential undefined behaviour in corner cases of floating-point-to-time conversions.
gh-101517: Fixed bug where
bdb
looks up the source line withlinecache
with alineno=None
, which causes it to fail with an unhandled exception.gh-101773: Optimize
fractions.Fraction
for small components. The private argument_normalize
of thefractions.Fraction
constructor has been removed.gh-101693: In
sqlite3.Cursor.execute()
,DeprecationWarning
is now emitted when named placeholders are used together with parameters supplied as a sequence instead of as adict
. Starting from Python 3.14, using named placeholders with parameters supplied as a sequence will raise aProgrammingError
. Patch by Erlend E. Aasland.gh-101446: Change repr of
collections.OrderedDict
to use regular dictionary formating instead of pairs of keys and values.gh-101362: Speed up
pathlib.PurePath
construction by handling arguments more uniformly. When apathlib.Path
argument is supplied, we use its string representation rather than joining its parts withos.path.join()
.gh-101362: Speed up
pathlib.PurePath
construction by callingos.path.join()
only when two or more arguments are given.gh-101362: Speed up
pathlib.Path
construction by running the path flavour compatibility check only when pathlib is imported.gh-85984: Refactored the implementation of
pty.fork()
to useos.login_tty()
.A
DeprecationWarning
is now raised bypty.master_open()
andpty.slave_open()
. They were undocumented and deprecated long long ago in the docstring in favor ofpty.openpty()
.gh-101561: Add a new decorator
typing.override()
. See PEP 698 for details. Patch by Steven Troxler.gh-101360: Fix anchor matching in
pathlib.PureWindowsPath.match()
. Path and pattern anchors are now matched withfnmatch
, just like other path parts. This allows patterns such as"*:/Users/*"
to be matched.gh-101277: Remove global state from
itertools
module (PEP 687). Patches by Erlend E. Aasland.gh-100809: Fix handling of drive-relative paths (like 'C:' and 'C:foo') in
pathlib.Path.absolute()
. This method now uses the OS API to retrieve the correct current working directory for the drive.gh-99138: Apply PEP 687 to
zoneinfo
. Patch by Erlend E. Aasland.gh-96764:
asyncio.wait_for()
now usesasyncio.timeout()
as its underlying implementation. Patch by Kumar Aditya.gh-88233: Correctly preserve "extra" fields in
zipfile
regardless of their ordering relative to a zip64 "extra."bpo-23224: Fix segfaults when creating
lzma.LZMADecompressor
andbz2.BZ2Decompressor
objects without calling__init__()
, and fix leakage of locks and internal buffers when calling the__init__()
methods oflzma.LZMADecompressor
,lzma.LZMACompressor
,bz2.BZ2Compressor
, andbz2.BZ2Decompressor
objects multiple times.
Documentation¶
gh-85417: Update
cmath
documentation to clarify behaviour on branch cuts.gh-97725: Fix
asyncio.Task.print_stack()
description forfile=None
. Patch by Oleg Iarygin.
Tests¶
gh-102019: Fix deadlock on shutdown if
test_current_{exception,frames}
fails. Patch by Jacob Bower.gh-85984: Utilize new "winsize" functions from termios in pty tests.
gh-89792:
test_tools
now copies up to 10x less source data to a temporary directory during thefreeze
test by ignoring git metadata and other artifacts. It also limits its python build parallelism based on os.cpu_count instead of hard coding it as 8 cores.
Build¶
gh-99942: On Android, in a static build, python-config in embed mode no longer incorrectly reports a library to link to.
gh-99942: On Android, python.pc now correctly reports the library to link to, the same as python-config.sh.
gh-100221: Fix creating install directories in
make sharedinstall
if they exist outsideDESTDIR
already.gh-96821: Explicitly mark C extension modules that need defined signed integer overflow, and add a configure option
--with-strict-overflow
. Patch by Matthias Görgens and Shantanu Jain.
Windows¶
gh-102344: Implement
winreg.QueryValue
usingQueryValueEx
andwinreg.SetValue
usingSetValueEx
. Patch by Max Bachmann.gh-101881: Handle read and write operations on non-blocking pipes properly on Windows.
gh-101881: Add support for the os.get_blocking() and os.set_blocking() functions on Windows.
gh-101849: Ensures installer will correctly upgrade existing
py.exe
launcher installs.gh-101763: Updates copy of libffi bundled with Windows installs to 3.4.4.
gh-101759: Update Windows installer to SQLite 3.40.1.
gh-101614: Correctly handle extensions built against debug binaries that reference
python3_d.dll
.gh-101196: The functions
os.path.isdir
,os.path.isfile
,os.path.islink
andos.path.exists
are now 13% to 28% faster on Windows, by making fewer Win32 API calls.
macOS¶
gh-101759: Update macOS installer to SQLite 3.40.1.
C API¶
gh-101907: Removes use of non-standard C++ extension in public header files.
gh-99293: Document that the Py_TPFLAGS_VALID_VERSION_TAG is an internal feature, should not be used, and will be removed.
gh-101578: Add
PyErr_GetRaisedException()
andPyErr_SetRaisedException()
for saving and restoring the current exception. These functions return and accept a single exception object, rather than the triple arguments of the now-deprecatedPyErr_Fetch()
andPyErr_Restore()
. This is less error prone and a bit more efficient.Add
PyException_GetArgs()
andPyException_SetArgs()
as convenience functions for retrieving and modifying theargs
passed to the exception's constructor.gh-91744: Introduced the Unstable C API tier, marking APi that is allowed to change in minor releases without a deprecation period. See PEP 689 for details.
Python 3.12.0 alpha 5¶
Release date: 2023-02-07
Security¶
Core and Builtins¶
gh-92173: Fix the
defs
andkwdefs
arguments toPyEval_EvalCodeEx()
and a reference leak in that function.gh-59956: The GILState API is now partially compatible with subinterpreters. Previously,
PyThreadState_GET()
andPyGILState_GetThisThreadState()
would get out of sync, causing inconsistent behavior and crashes.gh-101400: Fix wrong lineno in exception message on
continue
orbreak
which are not in a loop. Patch by Donghee Na.gh-101372: Fix
is_normalized()
to properly handle the UCD 3.2.0 cases. Patch by Donghee Na.gh-101266: Fix
sys.getsizeof()
reporting forint
subclasses.gh-101291: Refactor the
PyLongObject
struct into a normal Python object header and aPyLongValue
struct.gh-101046: Fix a possible memory leak in the parser when raising
MemoryError
. Patch by Pablo Galindogh-101037: Fix potential memory underallocation issue for instances of
int
subclasses with value zero.gh-100762: Record the (virtual) exception block depth in the oparg of
YIELD_VALUE
. Use this to avoid the expensivethrow()
when closing generators (and coroutines) that can be closed trivially.gh-100982: Adds a new
COMPARE_AND_BRANCH
instruction. This is a bit more efficient when performing a comparison immediately followed by a branch, and restores the design intent of PEP 659 that specializations are local to a single instruction.gh-100942: Fixed segfault in property.getter/setter/deleter that occurred when a property subclass overrode the
__new__
method to return a non-property instance.gh-100923: Remove the
mask
cache entry for theCOMPARE_OP
instruction and embed the mask into the oparg.gh-100892: Fix race while iterating over thread states in clearing
threading.local
. Patch by Kumar Aditya.gh-91351: Fix a case where re-entrant imports could corrupt the import deadlock detection code and cause a
KeyError
to be raised out ofimportlib/_bootstrap
. In addition to the straightforward cases, this could also happen when garbage collection leads to a warning being emitted -- as happens when it collects an open socket or file)gh-100726: Optimize construction of
range
object for medium size integers.gh-100712: Added option to build cpython with specialization disabled, by setting
ENABLE_SPECIALIZATION=False
inopcode
, followed bymake regen-all
.bpo-32780: Inter-field padding is now inserted into the PEP3118 format strings obtained from
ctypes.Structure
objects, reflecting their true representation in memory.
Library¶
gh-101541: [Enum] - fix psuedo-flag creation
gh-101570: Upgrade pip wheel bundled with ensurepip (pip 23.0)
gh-101323: Fix a bug where errors where not thrown by zlib._ZlibDecompressor if encountered during decompressing.
gh-101317: Add ssl_shutdown_timeout parameter for
asyncio.StreamWriter.start_tls()
.gh-101326: Fix regression when passing
None
as second or third argument toFutureIter.throw
.gh-92123: Adapt the
_elementtree
extension module to multi-phase init (PEP 489). Patches by Erlend E. Aasland.gh-100795: Avoid potential unexpected
freeaddrinfo
call (double free) insocket
when when a libcgetaddrinfo()
implementation leaves garbage in an output pointer when returning an error. Original patch by Sergey G. Brester.gh-101143: Remove unused references to
TimerHandle
inasyncio.base_events.BaseEventLoop._add_callback
.gh-101144: Make
zipfile.Path.open()
andzipfile.Path.read_text()
also acceptencoding
as a positional argument. This was the behavior in Python 3.9 and earlier. 3.10 introduced a regression where supplying it as a positional argument would lead to aTypeError
.gh-94518: Group-related variables of
_posixsubprocess
module are renamed to stress that supplimentary group affinity is added to a fork, not replace the inherited ones. Patch by Oleg Iarygin.gh-101015: Fix
typing.get_type_hints()
on'*tuple[...]'
and*tuple[...]
. It must not drop theUnpack
part.gh-101000: Add
os.path.splitroot()
, which splits a path into a 3-item tuple(drive, root, tail)
. This new function is used bypathlib
to improve the performance of path construction by up to a third.gh-100573: Fix a Windows
asyncio
bug with named pipes where a client doingos.stat()
on the pipe would cause an error in the server that disabled serving future requests.gh-39615:
warnings.warn()
now has the ability to skip stack frames based on code filename prefix rather than only a numericstacklevel
via the newskip_file_prefixes
keyword argument.gh-100750: pass encoding kwarg to subprocess in platform
gh-100160: Emit a deprecation warning in
asyncio.DefaultEventLoopPolicy.get_event_loop()
if there is no current event loop set and it decides to create one.gh-96290: Fix handling of partial and invalid UNC drives in
ntpath.splitdrive()
, and inntpath.normpath()
on non-Windows systems. Paths such as '\server' and '\' are now considered bysplitdrive()
to contain only a drive, and consequently are not modified bynormpath()
on non-Windows systems. The behaviour ofnormpath()
on Windows systems is unaffected, as native OS APIs are used. Patch by Eryk Sun, with contributions by Barney Gale.gh-99952: Fix a reference undercounting issue in
ctypes.Structure
withfrom_param()
results larger than a C pointer.gh-67790: Add float-style formatting support for
fractions.Fraction
instances.gh-86682: Ensure runtime-created collections have the correct module name using the newly added (internal)
sys._getframemodulename()
.gh-88597:
uuid
now has a command line interface. Trypython -m uuid -h
.gh-60580:
ctypes.wintypes.BYTE
definition changed fromc_byte
toc_ubyte
to match Windows SDK. Patch by Anatoly Techtonik and Oleg Iarygin.gh-94518:
_posixsubprocess
now initializes all UID and GID variables using a reserved-1
value instead of a separate flag. Patch by Oleg Iarygin.bpo-38941: The
xml.etree.ElementTree
module now emitsDeprecationWarning
when testing the truth value of anxml.etree.ElementTree.Element
. Before, the Python implementation emittedFutureWarning
, and the C implementation emitted nothing.bpo-40077: Convert
elementtree
types to heap types. Patch by Erlend E. Aasland.bpo-29847: Fix a bug where
pathlib.Path
accepted and ignored keyword arguments. Patch provided by Yurii Karabas.gh-77772:
ctypes.CDLL
,ctypes.OleDLL
,ctypes.WinDLL
, andctypes.PyDLL
now accept path-like objects as theirname
argument. Patch by Robert Hoelzl.
Documentation¶
gh-88324: Reword
subprocess
to emphasize default behavior of stdin, stdout, and stderr arguments. Remove inaccurate statement about child file handle inheritance.
Tests¶
gh-101334:
test_tarfile
has been updated to pass when run as a high UID.
Build¶
gh-101282: Update BOLT configration not to use depreacted usage of
--split functions
. Patch by Donghee Na.gh-101522: Allow overriding Windows dependencies versions and paths using MSBuild properties.
gh-77532: Minor fixes to allow building with
PlatformToolset=ClangCL
on Windows.gh-101152: In accordance with PEP 699, the
ma_version_tag
field inPyDictObject
is deprecated for extension modules. Accessing this field will generate a compiler warning at compile time. This field will be removed in Python 3.14.gh-100340: Allows -Wno-int-conversion for wasm-sdk 17 and onwards, thus enables building WASI builds once against the latest sdk.
gh-101060: Conditionally add
-fno-reorder-blocks-and-partition
in configure. Effectively fixes--enable-bolt
when using Clang, as this appears to be a GCC-only flag.gh-98705:
__bool__
is defined in AIX system header files which breaks the build in AIX, so undefine it.gh-98636: Fix a regression in detecting
gdbm_compat
library for the_gdbm
module build.gh-96305:
_aix_support
now uses a simple code to get platform details rather than the now non-existent_bootsubprocess
during bootstrap.
Windows¶
gh-101543: Ensure the install path in the registry is only used when the standard library hasn't been located in any other way.
gh-101467: The
py.exe
launcher now correctly filters when only a single runtime is installed. It also correctly handles prefix matches on tags so that-3.1
does not match3.11
, but would still match3.1-32
.gh-99834: Updates bundled copy of Tcl/Tk to 8.6.13.0
gh-101135: Restore ability to launch older 32-bit versions from the
py.exe
launcher when both 32-bit and 64-bit installs of the same version are available.gh-82052: Fixed an issue where writing more than 32K of Unicode output to the console screen in one go can result in mojibake.
gh-100320: Ensures the
PythonPath
registry key from an install is used when launching from a different copy of Python that relies on an existing install to provide a copy of its modules and standard library.gh-100247: Restores support for the
py.exe
launcher finding shebang commands in its configuration file using the full command name.
Python 3.12.0 alpha 4¶
Release date: 2023-01-10
Core and Builtins¶
gh-100776: Fix misleading default value in
input()
's__text_signature__
.gh-99005: Remove
UNARY_POSITIVE
,ASYNC_GEN_WRAP
andLIST_TO_TUPLE
, replacing them with intrinsics.gh-99005: Add new
CALL_INTRINSIC_1
instruction. RemoveIMPORT_STAR
,PRINT_EXPR
andSTOPITERATION_ERROR
, replacing them with theCALL_INTRINSIC_1
instruction.gh-100288: Remove the LOAD_ATTR_METHOD_WITH_DICT specialized instruction. Stats show it is not useful.
gh-100720: Added
_PyFrame_NumSlotsForCodeObject
, which returns the number of slots needed in a frame for a given code object.gh-100719: Removed the co_nplaincellvars field from the code object, as it is redundant.
gh-100637: Fix
int.__sizeof__()
calculation to include the 1 element ob_digit array for 0 and False.gh-100649: Update the native_thread_id field of PyThreadState after fork.
gh-100126: Fix an issue where "incomplete" frames could be briefly visible to C code while other frames are being torn down, possibly resulting in corruption or hard crashes of the interpreter while running finalizers.
gh-87447: Fix
SyntaxError
on comprehension rebind checking with names that are not actually redefined.Now reassigning
b
in[(b := 1) for a, b.prop in some_iter]
is allowed. Reassigninga
is still disallowed as per PEP 572.gh-100268: Add
int.is_integer()
to improve duck type compatibility betweenint
andfloat
.gh-100425: Improve the accuracy of
sum()
with compensated summation.gh-100374: Fix incorrect result and delay in
socket.getfqdn()
. Patch by Dominic Socular.gh-100357: Convert
vars
,dir
,next
,getattr
, anditer
to argument clinic.gh-100117: Improve the output of
co_lines
by emitting only one entry for each line range.gh-90043: Handle NaNs when specializing
COMPARE_OP
forfloat
values.gh-100222: Redefine the
_Py_CODEUNIT
typedef as a union to describe its layout to the C compiler, avoiding type punning and improving clarity.gh-99955: Internal compiler functions (in compile.c) now consistently return -1 on error and 0 on success.
gh-100188: The
BINARY_SUBSCR_LIST_INT
andBINARY_SUBSCR_TUPLE_INT
instructions are no longer used for negative integers because those instructions always miss when encountering negative integers.gh-99110: Initialize frame->previous in frameobject.c to fix a segmentation fault when accessing frames created by
PyFrame_New()
.gh-94155: Improved the hashing algorithm for code objects, mitigating some hash collisions.
gh-99540:
None
now hashes to a constant value. This is not a requirements change.gh-100143: When built with
--enable-pystats
, stats collection is now off by default. To enable it early at startup, pass the-Xpystats
flag. Stats are now always dumped, even if switched off.gh-100146: Improve
BUILD_LIST
opcode so that it works similarly to theBUILD_TUPLE
opcode, by stealing references from the stack rather than repeatedly using stack operations to set list elements. Implementation details are in a new private API_PyList_FromArraySteal()
.gh-100110: Specialize
FOR_ITER
for tuples.gh-100050: Honor existing errors obtained when searching for mismatching parentheses in the tokenizer. Patch by Pablo Galindo
gh-92216: Improve the performance of
hasattr()
for type objects with a missing attribute.gh-99554: Pack debugging location tables more efficiently during bytecode compilation.
gh-98522: Add an internal version number to code objects, to give better versioning of inner functions and comprehensions, and thus better specialization of those functions. This change is invisible to both Python and C extensions.
gh-94603: Improve performance of
list.pop
for small lists.bpo-32782:
ctypes
arrays of length 0 now report a correct itemsize when amemoryview
is constructed from them, rather than always giving a value of 0.
Library¶
gh-100833: Speed up
math.fsum()
by removing defensivevolatile
qualifiers.gh-100805: Modify
random.choice()
implementation to once again work with NumPy arrays.gh-100813: Add
socket.IP_PKTINFO
constant.gh-100792: Make
email.message.Message.__contains__()
twice as fast.gh-91851: Microoptimizations for
fractions.Fraction.__round__()
,fractions.Fraction.__ceil__()
andfractions.Fraction.__floor__()
.gh-90104: Avoid RecursionError on
repr
if a dataclass field definition has a cyclic reference.gh-100689: Fix crash in
pyexpat
by statically allocatingPyExpat_CAPI
capsule.gh-100740: Fix
unittest.mock.Mock
not respecting the spec for attribute names prefixed withassert
.gh-91219: Change
SimpleHTTPRequestHandler
to support subclassing to provide a different set of index file names instead of using__init__
parameters.gh-100690:
Mock
objects which are not unsafe will now raise anAttributeError
when accessing an attribute that matches the name of an assertion but without the prefixassert_
, e.g. accessingcalled_once
instead ofassert_called_once
. This is in addition to this already happening for accessing attributes with prefixesassert
,assret
,asert
,aseert
, andassrt
.gh-89727: Simplify and optimize
os.walk()
by usingisinstance()
checks to check the top of the stack.gh-100485: Add math.sumprod() to compute the sum of products.
gh-86508: Fix
asyncio.open_connection()
to skip binding to local addresses of different family. Patch by Kumar Aditya.gh-97930:
importlib.resources.files
now accepts a module as an anchor instead of only accepting packages. If a module is passed, resources are resolved adjacent to that module (in the same package or at the package root). The parameter was renamed frompackage
toanchor
with a compatibility shim for those passing by keyword. Additionally, the newanchor
parameter is now optional and will default to the caller's module.gh-100585: Fixed a bug where importlib.resources.as_file was leaving file pointers open
gh-100562: Improve performance of
pathlib.Path.absolute()
by nearly 2x. This comes at the cost of a performance regression inpathlib.Path.cwd()
, which is generally used less frequently in user code.gh-100519: Small simplification of
http.cookiejar.eff_request_host()
that improves readability and better matches the RFC wording.gh-100287: Fix the interaction of
unittest.mock.seal()
withunittest.mock.AsyncMock
.gh-100488: Add
Fraction.is_integer()
to check whether afractions.Fraction
is an integer. This improves duck type compatibility withfloat
andint
.gh-100474:
http.server
now checks that an index page is actually a regular file before trying to serve it. This avoids issues with directories namedindex.html
.gh-100363: Speed up
asyncio.get_running_loop()
by removing redundantgetpid
checks. Patch by Kumar Aditya.gh-78878: Fix crash when creating an instance of
_ctypes.CField
.gh-100348: Fix ref cycle in
asyncio._SelectorSocketTransport
by removing_read_ready_cb
inclose
.gh-100344: Provide C implementation for
asyncio.current_task()
for a 4x-6x speedup.gh-100272: Fix JSON serialization of OrderedDict. It now preserves the order of keys.
gh-83076: Instantiation of
Mock()
andAsyncMock()
is now 3.8x faster.gh-100234: Set a default value of 1.0 for the
lambd
parameter in random.expovariate().gh-100228: A
DeprecationWarning
may be raised whenos.fork()
oros.forkpty()
is called from multi-threaded processes. Forking with threads is unsafe and can cause deadlocks, crashes and subtle problems. Lack of a warning does not indicate that the fork call was actually safe, as Python may not be aware of all threads.gh-100039: Improve signatures for enums and flags.
gh-100133: Fix regression in
asyncio
where a subprocess would sometimes lose data received from pipe.bpo-44592: Fixes inconsistent handling of case sensitivity of extrasaction arg in
csv.DictWriter
.gh-100098: Fix
tuple
subclasses being cast totuple
when used as enum values.gh-85432: Rename the fmt parameter of the pure-Python implementation of
datetime.time.strftime()
to format. Rename the t parameter ofdatetime.datetime.fromtimestamp()
to timestamp. These changes mean the parameter names in the pure-Python implementation now match the parameter names in the C implementation. Patch by Alex Waygood.gh-98778: Update
HTTPError
to be initialized properly, even if thefp
isNone
. Patch by Donghee Na.gh-99925: Unify error messages in JSON serialization between
json.dumps(float('nan'), allow_nan=False)
andjson.dumps(float('nan'), allow_nan=False, indent=<SOMETHING>)
. Now both include the representation of the value that could not be serialized.gh-89727: Fix issue with
os.walk()
where aRecursionError
would occur on deep directory structures by adjusting the implementation ofos.walk()
to be iterative instead of recursive.gh-94943: Add 数据类支持 to the
Enum
__repr__()
. When inheriting from adataclass
, only show the field names in the value section of the memberrepr()
, and not the dataclass' class name.gh-83035: Fix
inspect.getsource()
handling of decorator calls with nested parentheses.gh-99576: Fix
.save()
method forLWPCookieJar
andMozillaCookieJar
: saved file was not truncated on repeated save.gh-94912: Add
inspect.markcoroutinefunction()
decorator which manually marks a function as a coroutine for the benefit ofiscoroutinefunction()
.gh-99509: Add PEP 585 support for
multiprocessing.queues.Queue
.gh-99482: Remove
Jython
partial compatibility code from several stdlib modules.gh-99433: Fix
doctest
failure ontypes.MethodWrapperType
in modules.gh-85267: Several improvements to
inspect.signature()
's handling of__text_signature
. - Fixes a case whereinspect.signature()
dropped parameters - Fixes a case whereinspect.signature()
raisedtokenize.TokenError
- Allowsinspect.signature()
to understand defaults involving binary operations of constants -inspect.signature()
is documented as only raisingTypeError
orValueError
, but sometimes raisedRuntimeError
. These cases now raiseValueError
- Removed a dead code pathgh-91166:
asyncio
is optimized to avoid excessive copying when writing to socket and usesendmsg()
if the platform supports it. Patch by Kumar Aditya.gh-98030: Add missing TCP socket options from Linux:
TCP_MD5SIG
,TCP_THIN_LINEAR_TIMEOUTS
,TCP_THIN_DUPACK
,TCP_REPAIR
,TCP_REPAIR_QUEUE
,TCP_QUEUE_SEQ
,TCP_REPAIR_OPTIONS
,TCP_TIMESTAMP
,TCP_CC_INFO
,TCP_SAVE_SYN
,TCP_SAVED_SYN
,TCP_REPAIR_WINDOW
,TCP_FASTOPEN_CONNECT
,TCP_ULP
,TCP_MD5SIG_EXT
,TCP_FASTOPEN_KEY
,TCP_FASTOPEN_NO_COOKIE
,TCP_ZEROCOPY_RECEIVE
,TCP_INQ
,TCP_TX_DELAY
.gh-88500: Reduced the memory usage of
urllib.parse.unquote()
andurllib.parse.unquote_to_bytes()
on large values.gh-96127:
inspect.signature
was raisingTypeError
on call with mock objects. Now it correctly returns(*args, **kwargs)
as infered signature.gh-95882: Fix a 3.11 regression in
asynccontextmanager()
, which caused it to propagate exceptions with incorrect tracebacks and fix a 3.11 regression incontextmanager()
, which caused it to propagate exceptions with incorrect tracebacks forStopIteration
.gh-78707: Deprecate passing more than one positional argument to
pathlib.PurePath.relative_to()
andis_relative_to()
.gh-92122: Fix reStructuredText syntax errors in docstrings in the
enum
module.gh-91851: Optimize the
Fraction
arithmetics for small components.bpo-24132: Make
pathlib.PurePath
andPath
subclassable (private to start). Previously, attempting to instantiate a subclass resulted in anAttributeError
being raised. Patch by Barney Gale.bpo-40447: Accept
os.PathLike
(such aspathlib.Path
) in thestripdir
arguments ofcompileall.compile_file()
andcompileall.compile_dir()
.bpo-36880: Fix a reference counting issue when a
ctypes
callback with return typepy_object
returnsNone
, which could cause crashes.
Documentation¶
gh-100616: Document existing
attr
parameter tocurses.window.vline()
function incurses
.gh-100472: Remove claim in documentation that the
stripdir
,prependdir
andlimit_sl_dest
parameters ofcompileall.compile_dir()
andcompileall.compile_file()
could bebytes
.bpo-25377: Clarify use of octal format of mode argument in help(os.chmod) as well as help(os.fchmod)
Tests¶
gh-100454: Start running SSL tests with OpenSSL 3.1.0-beta1.
gh-100086: The Python test runner (libregrtest) now logs Python build information like "debug" vs "release" build, or LTO and PGO optimizations. Patch by Victor Stinner.
gh-93018: Make two tests forgiving towards host system libexpat with backported security fixes applied.
Build¶
gh-100540: Removed the
--with-system-ffi
configure
option;libffi
must now always be supplied by the system on all non-Windows platforms. The option has had no effect on non-Darwin platforms for several releases, and in 3.11 only had the non-obvious effect of invokingpkg-config
to findlibffi
and never setting-DUSING_APPLE_OS_LIBFFI
. Now on Darwin platformsconfigure
will first check for the OSlibffi
and then fall back to the same processing as other platforms if it is not found.gh-88267: Avoid exporting Python symbols in linked Windows applications when the core is built as static.
bpo-41916: Allow override of ac_cv_cxx_thread so that cross compiled python can set -pthread for CXX.
Windows¶
gh-100180: Update Windows installer to OpenSSL 1.1.1s
gh-99191: Use
_MSVC_LANG >= 202002L
instead of less-precise_MSC_VER >=1929
to more accurately test for C++20 support inPC/_wmimodule.cpp
.gh-79218: Define
MS_WIN64
for Mingw-w64 64bit, fix cython compilation failure.gh-99941: Ensure that
asyncio.Protocol.data_received()
receives an immutablebytes
object (as documented), instead ofbytearray
.bpo-43984:
winreg.SetValueEx()
now leaves the target value untouched in the case of conversion errors. Previously,-1
would be written in case of such errors.bpo-34816:
hasattr(ctypes.windll, 'nonexistant')
now returnsFalse
instead of raisingOSError
.
macOS¶
Tools/Demos¶
bpo-45256: Fix a bug that caused an
AttributeError
to be raised inpython-gdb.py
whenpy-locals
is used without a frame.gh-100342: Add missing
NULL
check for possible allocation failure in*args
parsing in Argument Clinic.
C API¶
gh-99947: Raising SystemError on import will now have its cause be set to the original unexpected exception.
gh-99240: In argument parsing, after deallocating newly allocated memory, reset its pointer to NULL.
gh-98724: The
Py_CLEAR
,Py_SETREF
andPy_XSETREF
macros now only evaluate their arguments once. If an argument has side effects, these side effects are no longer duplicated. Patch by Victor Stinner.
Python 3.12.0 alpha 3¶
Release date: 2022-12-06
Security¶
gh-100001:
python -m http.server
no longer allows terminal control characters sent within a garbage request to be printed to the stderr server log.This is done by changing the
http.server
BaseHTTPRequestHandler
.log_message
method to replace control characters with a\xHH
hex escape before printing.gh-87604: Avoid publishing list of active per-interpreter audit hooks via the
gc
module
Core and Builtins¶
gh-99891: Fix a bug in the tokenizer that could cause infinite recursion when showing syntax warnings that happen in the first line of the source. Patch by Pablo Galindo
gh-91054: Add
PyCode_AddWatcher()
andPyCode_ClearWatcher()
APIs to register callbacks to receive notification on creation and destruction of code objects.gh-99729: Fix an issue that could cause frames to be visible to Python code as they are being torn down, possibly leading to memory corruption or hard crashes of the interpreter.
gh-99708: Fix bug where compiler crashes on an if expression with an empty body block.
gh-99578: Fix a reference bug in
_imp.create_builtin()
after the creation of the first sub-interpreter for modulesbuiltins
andsys
. Patch by Victor Stinner.gh-99581: Fixed a bug that was causing a buffer overflow if the tokenizer copies a line missing the newline caracter from a file that is as long as the available tokenizer buffer. Patch by Pablo galindo
gh-99553: Fix bug where an
ExceptionGroup
subclass can wrap aBaseException
.gh-99547: Add a function to os.path to check if a path is a junction: isjunction. Add similar functionality to pathlib.Path as is_junction.
gh-99370: Fix zip path for venv created from a non-installed python on POSIX platforms.
gh-99377: Add audit events for thread creation and clear operations.
gh-98686: Remove the
BINARY_OP_GENERIC
andCOMPARE_OP_GENERIC
"specializations".gh-99298: Remove the remaining error paths for attribute specializations, and refuse to specialize attribute accesses on types that haven't had
PyType_Ready()
called on them yet.gh-99127: Allow some features of
syslog
to the main interpreter only. Patch by Donghee Na.gh-91053: Optimizing interpreters and JIT compilers may need to invalidate internal metadata when functions are modified. This change adds the ability to provide a callback that will be invoked each time a function is created, modified, or destroyed.
gh-90994: Improve error messages when there's a syntax error with call arguments. The following three cases are covered: - No value is assigned to a named argument, eg
foo(a=)
. - A value is assigned to a star argument, egfoo(*args=[0])
. - A value is assigned to a double-star keyword argument, egfoo(**kwarg={'a': 0})
.bpo-45026: Optimize the
range
object iterator. It is now smaller, faster iteration of ranges containing large numbers. Smaller pickles, faster unpickling.bpo-31718: Raise
ValueError
instead ofSystemError
when methods of uninitializedio.IncrementalNewlineDecoder
objects are called. Patch by Oren Milman.bpo-38031: Fix a possible assertion failure in
io.FileIO
when the opener returns an invalid file descriptor.
Library¶
gh-100001: Also escape s in the http.server BaseHTTPRequestHandler.log_message so that it is technically possible to parse the line and reconstruct what the original data was. Without this a xHH is ambiguious as to if it is a hex replacement we put in or the characters r"x" came through in the original request line.
gh-99957: Add
frozen_default
parameter totyping.dataclass_transform()
.gh-79033: Fix
asyncio.Server.wait_closed()
to actually do what the docs promise -- wait for all existing connections to complete, after closing the server.gh-51524: Fix bug when calling trace.CoverageResults with valid infile.
gh-99645: Fix a bug in handling class cleanups in
unittest.TestCase
. NowaddClassCleanup()
uses separate lists for differentTestCase
subclasses, anddoClassCleanups()
only cleans up the particular class.gh-99508: Fix
TypeError
inLib/importlib/_bootstrap_external.py
while calling_imp.source_hash()
.gh-66285: Fix
asyncio
to not share event loop and signal wakeupfd in forked processes. Patch by Kumar Aditya.gh-97001: Release the GIL when calling termios APIs to avoid blocking threads.
gh-92647: Use final status of an enum to determine lookup or creation branch of functional API.
gh-99388: Add loop_factory parameter to
asyncio.run()
to allow specifying a custom event loop factory. Patch by Kumar Aditya.gh-99341: Fix
ast.increment_lineno()
to also coverast.TypeIgnore
when changing line numbers.gh-99382: Check the number of arguments in substitution in user generics containing a
TypeVarTuple
and one or moreTypeVar
.gh-99379: Fix substitution of
ParamSpec
followed byTypeVarTuple
in generic aliases.gh-99344: Fix substitution of
TypeVarTuple
andParamSpec
together in user generics.gh-99284: Remove
_use_broken_old_ctypes_structure_semantics_
old untested and undocumented hack fromctypes
.gh-99201: Fix
IndexError
when initializing the config variables on Windows ifHAVE_DYNAMIC_LOADING
is not set.gh-99240: Fix double-free bug in Argument Clinic
str_converter
by extracting memory clean up to a newpost_parsing
section.gh-64490: Fix refcount error when arguments are packed to tuple in Argument Clinic.
gh-99029:
pathlib.PurePath.relative_to()
now treats naked Windows drive paths as relative. This brings its behaviour in line with other parts of pathlib.gh-98253: The implementation of the typing module is now more resilient to reference leaks in binary extension modules.
Previously, a reference leak in a typed C API-based extension module could leak internals of the typing module, which could in turn introduce leaks in essentially any other package with typed function signatures. Although the typing package is not the original source of the problem, such non-local dependences exacerbate debugging of large-scale projects, and the implementation was therefore changed to reduce harm by providing better isolation.
gh-98458: Fix infinite loop in unittest when a self-referencing chained exception is raised
gh-93453:
asyncio.get_event_loop()
and many otherasyncio
functions likeasyncio.ensure_future()
,asyncio.shield()
orasyncio.gather()
, and also theget_event_loop()
method ofasyncio.BaseDefaultEventLoopPolicy
now raise aRuntimeError
if called when there is no running event loop and the current event loop was not set. Previously they implicitly created and set a new current event loop.DeprecationWarning
is no longer emitted if there is no running event loop but the current event loop was set.gh-97966: On
uname_result
, restored expectation that_fields
and_asdict
would include all six properties includingprocessor
.gh-98248: Provide informative error messages in
struct.pack()
when its integral arguments are not in range.gh-98108:
zipfile.Path
is now pickleable if its initialization parameters were pickleable (e.g. for file system paths).gh-98098: Created packages from zipfile and test_zipfile modules, separating
zipfile.Path
functionality.gh-82836: Fix
is_private
properties in theipaddress
module. Previously non-private networks (0.0.0.0/0) would return True from this method; now they correctly return False.gh-96828: Add an
OP_ENABLE_KTLS
option for enabling the use of the kernel TLS (kTLS). Patch by Illia Volochii.gh-88863: To avoid apparent memory leaks when
asyncio.open_connection()
raises, break reference cycles generated by local exception and future instances (which has exception instance as its member var). Patch by Dong Uk, Kang.gh-91078:
TarFile.next()
now returnsNone
when called on an empty tarfile.bpo-47220: Document the optional callback parameter of
WeakMethod
. Patch by Géry Ogam.bpo-44817: Ignore WinError 53 (ERROR_BAD_NETPATH), 65 (ERROR_NETWORK_ACCESS_DENIED) and 161 (ERROR_BAD_PATHNAME) when using ntpath.realpath().
bpo-41260: Rename the fmt parameter of the pure Python implementation of
datetime.date.strftime()
to format.bpo-15999: All built-in functions now accept arguments of any type instead of just
bool
andint
for boolean parameters.
Documentation¶
gh-99931: Use sphinxext-opengraph to generate OpenGraph metadata.
gh-89682: Reworded docstring of the default
__contains__
to clarify that it returns abool
.gh-88330: Improved the description of what a resource is in importlib.resources docs.
gh-92892: Document that calling variadic functions with ctypes requires special care on macOS/arm64 (and possibly other platforms).
bpo-41825: Restructured the documentation for the
os.wait*
family of functions, and improved the docs foros.waitid()
with more explanation of the possible argument constants.
Tests¶
gh-99892: Skip test_normalization() of test_unicodedata if it fails to download NormalizationTest.txt file from pythontest.net. Patch by Victor Stinner.
gh-99934: Correct test_marsh on (32 bit) x86: test_deterministic sets was failing.
gh-99741: We've implemented multi-phase init (PEP 489/630/687) for the internal (for testing) _xxsubinterpreters module.
gh-99659: Optional big memory tests in
test_sqlite3
now catch the correctsqlite.DataError
exception type in case of too large strings and/or blobs passed.gh-99593: Cover the Unicode C API with tests.
gh-96002: Add functional test for Argument Clinic.
Build¶
gh-99086: Fix
-Wimplicit-int
,-Wstrict-prototypes
, and-Wimplicit-function-declaration
compiler warnings in configure checks.gh-99337: Fix a compilation issue with GCC 12 on macOS.
gh-99289: Add a
COMPILEALL_OPTS
variable in Makefile to overridecompileall
options (default:-j0
) inmake install
. Also merged thecompileall
commands into a single command building .pyc files for the all optimization levels (0, 1, 2) at once. Patch by Victor Stinner.gh-98872: Fix a possible fd leak in
Programs/_freeze_module.c
introduced in Python 3.11.gh-88226: Always define
TARGET_*
labels inPython/ceval.c
, even ifUSE_COMPUTED_GOTOS
is disabled. This allows breakpoints to be set at those labels in (for instance)gdb
.
Windows¶
gh-99345: Use faster initialization functions to detect install location for Windows Store package
gh-98629: Fix initialization of
sys.version
andsys._git
on Windowsgh-99442: Fix handling in 适用于Windows的Python启动器 when
argv[0]
does not include a file extension.bpo-40882: Fix a memory leak in
multiprocessing.shared_memory.SharedMemory
on Windows.
macOS¶
Tools/Demos¶
gh-64490: Argument Clinic varargs bugfixes
Fix out-of-bounds error in
_PyArg_UnpackKeywordsWithVararg()
.Fix incorrect check which allowed more than one varargs in clinic.py.
Fix miscalculation of
noptargs
in generated code.Do not generate
noptargs
when there is a vararg argument and no optional argument.
C API¶
gh-98680:
PyBUF_*
constants were marked as part of Limited API of Python 3.11+. These were available in 3.11.0 withPy_LIMITED_API
defined for 3.11, and are necessary to use the buffer API.gh-99612: Fix
PyUnicode_DecodeUTF8Stateful()
for ASCII-only data:*consumed
was not set.gh-47146: The
structmember.h
header is deprecated. Its non-deprecated contents are now available just by includingPython.h
, with aPy_
prefix added if it was missing. (Deprecated contents areT_OBJECT
,T_NONE
, and no-op flags.) Patch by Petr Viktorin, based on earlier work by Alexander Belopolsky and Matthias Braun.
Python 3.12.0 alpha 2¶
Release date: 2022-11-14
Security¶
gh-98433: The IDNA codec decoder used on DNS hostnames by
socket
orasyncio
related name resolution functions no longer involves a quadratic algorithm. This prevents a potential CPU denial of service if an out-of-spec excessive length hostname involving bidirectional characters were decoded. Some protocols such asurllib
http3xx
redirects potentially allow for an attacker to supply such a name.Individual labels within an IDNA encoded DNS name will now raise an error early during IDNA decoding if they are longer than 1024 unicode characters given that each decoded DNS label must be 63 or fewer characters and the entire decoded DNS name is limited to 255. Only an application presenting a hostname or label consisting primarily of RFC 3454 section 3.1 "Nothing" characters to be removed would run into of this new limit. See also RFC 5894 section 6 and RFC 3491.
gh-98739: Update bundled libexpat to 2.5.0
Core and Builtins¶
gh-81057: The docs clearly say that
PyImport_Inittab
,PyImport_AppendInittab()
, andPyImport_ExtendInittab()
should not be used afterPy_Initialize()
has been called. We now enforce this for the two functions. Additionally, the runtime now uses an internal copy ofPyImport_Inittab
, to guard against modification.gh-99298: Fix an issue that could potentially cause incorrect error handling for some bytecode instructions.
gh-99254: The compiler now removes all unused constants from code objects (except the first one, which may be a docstring).
gh-99205: Fix an issue that prevented
PyThreadState
andPyInterpreterState
memory from being freed properly.gh-81057: The 18 global C variables holding the state of the allocators have been moved to
_PyRuntimeState
. This is a strictly internal change with no change in behavior.gh-99181: Fix failure in
except*
with unhashable exceptions.gh-99204: Fix calculation of
sys._base_executable
when inside a POSIX virtual environment using copies of the python binary when the base installation does not provide the executable name used by the venv. Calculation will fall back to alternative names ("python<MAJOR>", "python<MAJOR>.<MINOR>").gh-96055: Update
faulthandler
to emit an error message with the proper unexpected signal number. Patch by Donghee Na.gh-99153: Fix location of
SyntaxError
for atry
block with bothexcept
andexcept*
.gh-98686: Merge the adaptive opcode logic into each instruction's unquickened variant, and merge the logic in
EXTENDED_ARG_QUICK
intoEXTENDED_ARG
. With these changes, the quickening that happens at code object creation is now only responsible for initializing warmup counters and inserting superinstructions.gh-99103: Fix the error reporting positions of specialized traceback anchors when the source line contains Unicode characters.
gh-99139: Improve the error suggestion for
NameError
exceptions for instances. Now if aNameError
is raised in a method and the instance has an attribute that's exactly equal to the name in the exception, the suggestion will includeself.<NAME>
instead of the closest match in the method scope. Patch by Pablo Galindogh-98401: Octal escapes with value larger than
0o377
(ex:"\477"
), deprecated in Python 3.11, now produce aSyntaxWarning
, instead ofDeprecationWarning
. In a future Python version they will be eventually aSyntaxError
. Patch by Victor Stinner.gh-98401: A backslash-character pair that is not a valid escape sequence now generates a
SyntaxWarning
, instead ofDeprecationWarning
. For example,re.compile("\d+\.\d+")
now emits aSyntaxWarning
("\d"
is an invalid escape sequence), use raw strings for regular expression:re.compile(r"\d+\.\d+")
. In a future Python version,SyntaxError
will eventually be raised, instead ofSyntaxWarning
. Patch by Victor Stinner.gh-96793: Handle StopIteration and StopAsyncIteration raised in generator or coroutines in the bytecode, rather than in wrapping C code.
gh-98931: Improve the
SyntaxError
error message when the user typesimport x from y
instead offrom y import x
. Patch by Pablo Galindogh-98852: Fix subscription of type aliases containing bare generic types or types like
TypeVar
: for exampletuple[A, T][int]
andtuple[TypeVar, T][int]
, whereA
is a generic type, andT
is a type variable.gh-98925: Lower the recursion depth for marshal on WASI to support (in-development) wasmtime 2.0.
gh-98783: Fix multiple crashes in debug mode when
str
subclasses are used instead ofstr
itself.gh-98811: Use complete source locations to simplify detection of
__future__
imports which are not at the beginning of the file. Also corrects the offset in the exception raised in one case, which was off by one and impeded highlighting.gh-96793: Add specialization of
FOR_ITER
for generators. Saves multiple layers of dispatch and checking to get from theFOR_ITER
instruction in the caller to theRESUME
in the generator.gh-98586: Added the methods
PyObject_Vectorcall()
andPyObject_VectorcallMethod()
to the Limited API along with the auxiliary macro constantPY_VECTORCALL_ARGUMENTS_OFFSET
.The availability of these functions enables more efficient PEP 590 vector calls from binary extension modules that avoid argument boxing/unboxing overheads.
gh-99257: Fix an issue where member descriptors (such as those for
__slots__
) could behave incorrectly or crash instead of raising aTypeError
when accessed via an instance of an invalid type.gh-93143: Rather than changing
co_code
, the interpreter will now display aRuntimeWarning
and assignNone
to any fast locals that are left unbound after jumps ordel
statements executed while tracing.gh-96421: When calling into Python code from C code, through
PyEval_EvalFrameEx()
or a related C-API function, a shim frame in inserted into the call stack. This occurs in the_PyEval_EvalFrameDefault()
function. The extra frame should be invisible to all Python and most C extensions, but out-of-process profilers and debuggers need to be aware of it. These shim frames can be detected by checkingframe->owner == FRAME_OWNED_BY_CSTACK
.Extensions implementing their own interpreters using PEP 523 need to be aware of this shim frame and the changes to the semantics of
RETURN_VALUE
,YIELD_VALUE
, andRETURN_GENERATOR
, which now clear the frame.gh-98415: Fix detection of MAC addresses for
uuid
on certain OSs. Patch by Chaim Sandersgh-98686: Quicken all code objects, and specialize adaptive bytecode instructions more aggressively.
gh-92119: Print exception class name instead of its string representation when raising errors from
ctypes
calls.gh-91058:
ImportError
raised from failedfrom <module> import <name>
now include suggestions for the value of<name>
based on the available names in<module>
. Patch by Pablo Galindogh-96793: The
FOR_ITER
now leaves the iterator on the stack on termination of the loop. This is to assist specialization of loops for generators.gh-90716: Add _pylong.py module. It includes asymptotically faster algorithms that can be used for operations on integers with many digits. It is used by longobject.c to speed up some operations.
gh-95389: Expose
ETH_P_ALL
and some of the ETHERTYPE_* constants insocket
. Patch by Noam Cohen.gh-93696: Allow
pdb
to locate source for frozen modules in the standard library.
Library¶
gh-99418: Fix bug in
urllib.parse.urlparse()
that causes URL schemes that begin with a digit, a plus sign, or a minus sign to be parsed incorrectly.gh-94597: Deprecate
asyncio.AbstractChildWatcher
to be removed in Python 3.14. Patch by Kumar Aditya.gh-99305: Improve performance of
secrets.token_hex()
.gh-74044: Fixed bug where
inspect.signature()
reported incorrect arguments for decorated methods.gh-99275: Fix
SystemError
inctypes
when exception was not set during__initsubclass__
.gh-99277: Remove older version of
_SSLProtocolTransport.get_write_buffer_limits
inasyncio.sslproto
gh-99248: fix negative numbers failing in verify()
gh-99155: Fix
statistics.NormalDist
pickle with0
and1
protocols.gh-93464:
enum.auto()
is now correctly activated when combined with other assignment values. E.g.ONE = auto(), 'some text'
will now evaluate as(1, 'some text')
.gh-99134: Update the bundled copy of pip to version 22.3.1.
gh-92584: Remove the
distutils
package. It was deprecated in Python 3.10 by PEP 632 "Deprecate distutils module". For projects still usingdistutils
and cannot be updated to something else, thesetuptools
project can be installed: it still providesdistutils
. Patch by Victor Stinner.gh-98999: Now
_pyio
is consistent with_io
in raisingValueError
when executing methods over closed buffers.gh-83004: Clean up refleak on failed module initialisation in
_zoneinfo
gh-83004: Clean up refleaks on failed module initialisation in
_pickle
gh-83004: Clean up refleak on failed module initialisation in
_io
.gh-98897: Fix memory leak in
math.dist()
when both points don't have the same dimension. Patch by Kumar Aditya.gh-98878: Use the frame bound builtins when offering a name suggestion in
traceback
to prevent crashing when__builtins__
is not a dict.gh-98139: In
importlib._bootstrap
, enhance namespace package repr to<module 'x' (namespace) from ['path']>
.gh-90352: Fix
_SelectorDatagramTransport
to inherit fromDatagramTransport
inasyncio
. Patch by Kumar Aditya.gh-98793: Fix argument typechecks in
_overlapped.WSAConnect()
and_overlapped.Overlapped.WSASendTo()
functions.gh-98744: Prevent crashing in
traceback
when retrieving the byte-offset for some source files that contain certain unicode characters.gh-98740: Fix internal error in the
re
module which in very rare circumstances prevented compilation of a regular expression containing a conditional expression without the "else" branch.gh-98703: Fix
asyncio.StreamWriter.drain()
to callprotocol.connection_lost
callback only once on Windows.gh-98624: Add a mutex to unittest.mock.NonCallableMock to protect concurrent access to mock attributes.
gh-98658: The
array.array
class now supports subscripting, making it a generic type.gh-98284: Improved
TypeError
message for undefined abstract methods of aabc.ABC
instance. The names of the missing methods are surrounded by single-quotes to highlight them.gh-96151: Allow
BUILTINS
to be a valid field name for frozen dataclasses.gh-98086: Make sure
patch.dict()
can be applied on async functions.gh-72719: Remove modules
asyncore
andasynchat
, which were deprecated by PEP 594.gh-96192: Fix handling of
bytes
path-like objects inos.ismount()
.gh-94172:
ftplib
: Remove theFTP_TLS.ssl_version
class attribute: use the context parameter instead. Patch by Victor Stinnergh-94172: Remove the keyfile and certfile parameters from the
ftplib
,imaplib
,poplib
andsmtplib
modules, and the key_file, cert_file and check_hostname parameters from thehttp.client
module, all deprecated since Python 3.6. Use the context parameter (ssl_context inimaplib
) instead. Patch by Victor Stinner.gh-83638: Add the
autocommit
attribute tosqlite3.Connection
and the autocommit parameter tosqlite3.connect()
to control PEP 249-compliant transaction handling. Patch by Erlend E. Aasland.gh-92452: Fixed a race condition that could cause
sysconfig.get_config_var()
to incorrectly returnNone
in multi-threaded programs.gh-91803: Fix an error when using a method of objects mocked with
unittest.mock.create_autospec()
after it was sealed withunittest.mock.seal()
function.bpo-38523:
shutil.copytree()
now applies the ignore_dangling_symlinks argument recursively.bpo-40358: Add walk_up argument in
pathlib.PurePath.relative_to()
.bpo-36267: Fix IndexError in
argparse.ArgumentParser
when astore_true
action is given an explicit argument.
Documentation¶
gh-98832: Changes wording of docstring for
pathlib.Path.iterdir()
.gh-97966: Update uname docs to clarify the special nature of the platform attribute and to indicate when it became late-bound.
Tests¶
gh-98903: The Python test suite now fails wit exit code 4 if no tests ran. It should help detecting typos in test names and test methods.
gh-98713: Fix a bug in the
typing
tests where a test relying on CPython-specific implementation details was not decorated with@cpython_only
and was not skipped on other implementations.gh-87390: Add tests for star-unpacking with PEP 646, and some other miscellaneous PEP 646 tests.
gh-96853: Added explicit coverage of
Py_Initialize
(and hencePy_InitializeEx
) back to the embedding tests (all other embedding tests migrated toPy_InitializeFromConfig
in Python 3.11)bpo-34272: Some C API tests were moved into the new Lib/test/test_capi/ directory.
Build¶
gh-99086: Fix
-Wimplicit-int
compiler warning in configure check forPTHREAD_SCOPE_SYSTEM
.gh-99016: Fix build with
PYTHON_FOR_REGEN=python3.8
.gh-97731: Specify the full path to the source location for
make docclean
(needed for cross-builds).gh-98949: Drop unused build dependency on
readelf
.gh-98989: Use
python3.11
, if available, for regeneration and freezing.gh-98831: Add new tooling, in
Tools/cases_generator
, to generate the interpreter switch statement from a list of opcode definitions. This only affects adding, modifying or removing instruction definitions. The instruction definitions now live inPython/bytecodes.c
, in the form of a custom DSL (under development). The tooling reads this file and writesPython/generated_cases.c.h
, which is then included byPython/ceval.c
to provide most of the cases of the main interpreter switch.gh-98817: Remove PCbuild/lib.pyproj: it's not used for anything, is only a minor convenience for Visual Studio users (who probably mostly don't even know about it), and it takes a lot of maintenance effort to keep updated.
gh-98776: Fix
make regen-test-levenshtein
for out-of-tree builds.gh-98707: Don't use vendored
libmpdec
headers if--with-system-libmpdec
is passed to configure. Don't use vendoredlibexpat
headers if--with-system-expat
is passed to configure.
Windows¶
gh-98689: Update Windows builds to zlib v1.2.13. v1.2.12 has CVE-2022-37434, but the vulnerable
inflateGetHeader
API is not used by Python.gh-98790: Assumes that a missing
DLLs
directory means that standard extension modules are in the executable's directory.gh-98745: Update
py.exe
launcher to install 3.11 by default and 3.12 on request.gh-98692: Fix the 适用于Windows的Python启动器 ignoring unrecognized shebang lines instead of treating them as local paths
gh-94328: Update Windows installer to use SQLite 3.39.4.
macOS¶
gh-94328: Update macOS installer to SQLite 3.39.4.
C API¶
gh-98724: The
Py_CLEAR
,Py_SETREF
andPy_XSETREF
macros now only evaluate their argument once. If the argument has side effects, these side effects are no longer duplicated. Patch by Victor Stinner.gh-98978: Fix use-after-free in
Py_SetPythonHome(NULL)
,Py_SetProgramName(NULL)
and_Py_SetProgramFullPath(NULL)
function calls. Issue reported by Benedikt Reinartz. Patch by Victor Stinner.gh-98410: Add
getbufferproc
andreleasebufferproc
to the stable API.gh-98610: Some configurable capabilities of sub-interpreters have changed. They always allow subprocesses (
subprocess
) now, whereas before subprocesses could be optionally disallowed for a sub-interpreter. Insteados.exec()
can now be disallowed. Disallowing daemon threads is now supported. Disallowing all threads is still allowed, but is never done by default. Note that the optional restrictions are only available through_Py_NewInterpreterFromConfig()
, which isn't a public API. They do not affect the main interpreter, norPy_NewInterpreter()
.gh-98608: A
_PyInterpreterConfig
has been added and_Py_NewInterpreter()
has been renamed to_Py_NewInterpreterFromConfig()
. The "isolated_subinterpreters" argument is now a granular config that captures the previous behavior. Note that this is all "private" API.gh-96853:
Py_InitializeEx
now correctly callsPyConfig_Clear
after initializing the interpreter (the omission didn't cause a memory leak only because none of the dynamically allocated config fields are populated by the wrapper function)gh-91248: Add
PyFrame_GetVar()
andPyFrame_GetVarString()
functions to get a frame variable by its name. Patch by Victor Stinner.
Python 3.12.0 alpha 1¶
Release date: 2022-10-25
Security¶
gh-97616: Fix multiplying a list by an integer (
list *= int
): detect the integer overflow when the new allocated length is close to the maximum size. Issue reported by Jordan Limor. Patch by Victor Stinner.gh-97514: On Linux the
multiprocessing
module returns to using filesystem backed unix domain sockets for communication with the forkserver process instead of the Linux abstract socket namespace. Only code that chooses to use the "forkserver" start method is affected.Abstract sockets have no permissions and could allow any user on the system in the same network namespace (often the whole system) to inject code into the multiprocessing forkserver process. This was a potential privilege escalation. Filesystem based socket permissions restrict this to the forkserver process user as was the default in Python 3.8 and earlier.
This prevents Linux CVE-2022-42919.
gh-87389:
http.server
: Fix an open redirection vulnerability in the HTTP server when an URI path starts with//
. Vulnerability discovered, and initial fix proposed, by Hamza Avvan.gh-79096: LWPCookieJar and MozillaCookieJar create files with file mode 600 instead of 644 (Microsoft Windows is not affected)
gh-92888: Fix
memoryview
use after free when accessing the backing buffer in certain cases.gh-68966: The deprecated mailcap module now refuses to inject unsafe text (filenames, MIME types, parameters) into shell commands. Instead of using such text, it will warn and act as if a match was not found (or for test commands, as if the test failed).
Core and Builtins¶
gh-98374: Suppress ImportError for invalid query for help() command. Patch by Donghee Na.
gh-98461: Fix source location in bytecode for list, set and dict comprehensions as well as generator expressions.
gh-98354: Added unicode check for
name
attribute ofspec
argument passed in_imp.create_builtin()
function.gh-98398: Fix source location of 'assert' bytecodes.
gh-98390: Fix location of sub-expressions of boolean expressions, by reducing their scope to that of the sub-expression.
gh-98254: Modules from the standard library are now potentially suggested as part of the error messages displayed by the interpreter when an
NameError
is raised to the top level. Patch by Pablo Galindogh-97997: Add running column offset to the tokenizer state to avoid calculating AST column information with pointer arithmetic.
gh-97973: Modify the tokenizer to return all necessary information the parser needs to set location information in the AST nodes, so that the parser does not have to calculate those doing pointer arithmetic.
gh-96078:
os.sched_yield()
now release the GIL while calling sched_yield(2). Patch by Donghee Na.gh-97912: The compiler now avoids quadratic behavior when finding which instructions should use the
LOAD_FAST_CHECK
opcode.gh-97002: Fix an issue where several frame objects could be backed by the same interpreter frame, possibly leading to corrupted memory and hard crashes of the interpreter.
gh-97943: Bugfix:
PyFunction_GetAnnotations()
should return a borrowed reference. It was returning a new reference.gh-97922: The Garbage Collector now runs only on the eval breaker mechanism of the Python bytecode evaluation loop instead on object allocations. The GC can also run when
PyErr_CheckSignals()
is called so C extensions that need to run for a long time without executing any Python code also have a chance to execute the GC periodically.gh-65961: When
__package__
is different than__spec__.parent
, raise aDeprecationWarning
instead ofImportWarning
.Also remove
importlib.util.set_package()
which was scheduled for removal.gh-97850: Long deprecated,
module_repr()
should now be completely eradicated.gh-86298: In cases where
warnings.warn_explicit()
consults the module's loader, anDeprecationWarning
is issued whenm.__loader__
differs fromm.__spec__.loader
.gh-97779: Ensure that all Python frame objects are backed by "complete" frames.
gh-91052: Add API for subscribing to modification events on selected dictionaries.
gh-97752: Fix possible data corruption or crashes when accessing the
f_back
member of newly-created generator or coroutine frames.gh-97591: Fixed a missing incref/decref pair in
Exception.__setstate__()
. Patch by Ofey Chan.gh-97670: Remove the
sys.getdxp()
function and theTools/scripts/analyze_dxp.py
script. DXP stands for "dynamic execution pairs". They were related toDYNAMIC_EXECUTION_PROFILE
andDXPAIRS
macros which have been removed in Python 3.11. Python can now be built with./configure --enable-pystats
to gather statistics on Python opcodes. Patch by Victor Stinner.gh-94526: Fix the Python path configuration used to initialized
sys.path
at Python startup. Paths are no longer encoded to UTF-8/strict to avoid encoding errors if it contains surrogate characters (bytes paths are decoded with the surrogateescape error handler). Patch by Victor Stinner.gh-96670: The parser now raises
SyntaxError
when parsing source code containing null bytes. Patch by Pablo Galindogh-96975: Fix a crash occurring when
PyEval_GetFrame()
is called while the topmost Python frame is in a partially-initialized state.gh-96848: Fix command line parsing: reject
-X int_max_str_digits
option with no value (invalid) when thePYTHONINTMAXSTRDIGITS
environment variable is set to a valid limit. Patch by Victor Stinner.gh-95921: Fix overly-broad source position information for chained comparisons used as branching conditions.
gh-96821: Fix undefined behaviour in
audioop.c
.gh-96821: Fix undefined behaviour in
_testcapimodule.c
.gh-95778: When
ValueError
is raised if an integer is larger than the limit, mention thesys.set_int_max_str_digits()
function in the error message. Patch by Victor Stinner.gh-96387: At Python exit, sometimes a thread holding the GIL can wait forever for a thread (usually a daemon thread) which requested to drop the GIL, whereas the thread already exited. To fix the race condition, the thread which requested the GIL drop now resets its request before exiting. Issue discovered and analyzed by Mingliang ZHAO. Patch by Victor Stinner.
gh-96864: Fix a possible assertion failure, fatal error, or
SystemError
if a line tracing event raises an exception while opcode tracing is enabled.gh-95778: The
PyLong_FromString
function was refactored to make it more maintainable and extensible.gh-96678: Fix undefined behaviour in C code of null pointer arithmetic.
gh-96754: Make sure that all frame objects created are created from valid interpreter frames. Prevents the possibility of invalid frames in backtraces and signal handlers.
gh-90997: Improve the performance of reading and writing inline bytecode caches on some platforms.
gh-96751: Remove dead code from
CALL_FUNCTION_EX
opcode.gh-90751:
memoryview
now supports half-floats. Patch by Donghee Na and Antoine Pitrou.gh-96678: Fix case of undefined behavior in ceval.c
gh-64373: Convert
_functools
to argument clinic.gh-96641: Do not expose
KeyWrapper
in_functools
.gh-96636: Ensure that tracing,
sys.setrace()
, is turned on immediately. In pre-release versions of 3.11, some tracing events might have been lost when turning on tracing in a__del__
method or interrupt.gh-96572: Fix use after free in trace refs build mode. Patch by Kumar Aditya.
gh-96611: When loading a file with invalid UTF-8 inside a multi-line string, a correct SyntaxError is emitted.
gh-96612: Make sure that incomplete frames do not show up in tracemalloc traces.
gh-90230: Fix compiler warnings and test failures when building with
--enable-pystats
.gh-96587: Correctly raise
SyntaxError
on exception groups (PEP 654) on python versions prior to 3.11gh-96569: Remove two cases of undefined behavoir, by adding NULL checks.
gh-96582: Fix possible
NULL
pointer dereference in_PyThread_CurrentFrames
. Patch by Kumar Aditya.gh-91079: Separate Python recursion checking from C recursion checking which reduces the chance of C stack overflow and allows the recursion limit to be increased safely.
gh-93911: Fix an issue that could prevent
LOAD_ATTR
from specializing properly when accessing properties.gh-96348: Emit a DeprecationWarning when
throw()
,throw()
orathrow()
are called with more than one argument.gh-95196: Disable incorrect pickling of the C implemented classmethod descriptors.
gh-96364: Fix text signatures of
list.__getitem__
anddict.__getitem__
.gh-96352: Fix
AttributeError
missingname
andobj
attributes inobject.__getattribute__()
. Patch by Philip Georgi.gh-93554: Change the jump opcodes so that all conditional jumps are forward jumps. Backward jumps are converted by the assembler into a conditional forward jump whose target is the fallthrough block (and with a reversed condition), followed by an unconditional backward jump. For example:
POP_JUMP_IF_TRUE BACKWARD_TARGET
becomesPOP_JUMP_IF_FALSE NEXT_BLOCK; JUMP BACKWARD_TARGET
.All the directed conditional jump opcodes were removed:
POP_JUMP_FORWARD_IF_TRUE
,POP_JUMP_BACKWARD_IF_TRUE
,POP_JUMP_FORWARD_IF_FALSE
,POP_JUMP_BACKWARD_IF_FALSE
,POP_JUMP_FORWARD_IF_NONE
,POP_JUMP_BACKWARD_IF_NONE
,POP_JUMP_FORWARD_IF_NOT_NONE
,POP_JUMP_BACKWARD_IF_NOT_NONE
.The corresponding opcodes without direction are no longer pseudo-instructions, and they implement the forward conditional jumps.
gh-96268: Loading a file with invalid UTF-8 will now report the broken character at the correct location.
gh-96237: The internal field
_PyInterpreterFrame.f_func
is renamed to_PyInterpreterFrame.f_funcobj
and may be any object. Thef_globals
andf_builtin
fields may hold junk values.It is safest to treat the
_PyInterpreterFrame
struct as opaque.gh-96187: Fixed a bug that caused
_PyCode_GetExtra
to return garbage for negative indexes. Patch by Pablo Galindogh-96143: Add a new
-X perf
Python command line option as well assys.activate_stack_trampoline()
andsys.deactivate_stack_trampoline()
function in thesys
module that allows to set/unset the interpreter in a way that the Linuxperf
profiler can detect Python calls. The newsys.is_stack_trampoline_active()
function allows to query the state of the perf trampoline. Design by Pablo Galindo. Patch by Pablo Galindo and Christian Heimes with contributions from Gregory P. Smith [Google] and Mark Shannon.gh-96071: Fix a deadlock in
PyGILState_Ensure()
when allocating new thread state. Patch by Kumar Aditya.gh-96046:
PyType_Ready()
now initializesht_cached_keys
and performs additional checks to ensure that type objects are properly configured. This avoids crashes in 3rd party packages that don't use regular API to create new types.gh-96005: On WASI
ENOTCAPABLE
is now mapped toPermissionError
. Theerrno
modules exposes the new error number.getpath.py
now ignoresPermissionError
when it cannot open landmark filespybuilddir.txt
andpyenv.cfg
.gh-93678: Added test a harness for direct unit tests of the compiler's optimization stage. The
_testinternalcapi.optimize_cfg()
function runs the optimiser on a sequence of instructions. TheCfgOptimizationTestCase
class intest.support
has utilities for invoking the optimizer and checking the output.gh-95245: Reduces the size of a "simple" Python object from 8 to 6 words by moving the weakreflist pointer into the pre-header directly before the object's dict/values pointer.
gh-90997: Compile virtual
try
/except
blocks to handle exceptions raised duringclose()
orthrow()
calls through a suspended frame.gh-95977: Optimized calling
__get__()
with vectorcall. Patch by Kumar Aditya.gh-91210: Improve error message when a parameter without a default value follows one with a default value, and show the same message, even when the non-default/default sequence is preceded by positional-only parameters.
gh-95922: Fixed bug where the compiler's
eliminate_empty_basic_blocks
function ignores the last block of the code unit.gh-95818: Skip over incomplete frames in
PyThreadState_GetFrame()
.gh-95876: Fix format string in
_PyPegen_raise_error_known_location
that can lead to memory corruption on some 64bit systems. The function was building a tuple withi
(int) instead ofn
(Py_ssize_t) for Py_ssize_t arguments.gh-95605: Fix misleading contents of error message when converting an all-whitespace string to
float
.gh-95150: Update code object hashing and equality to consider all debugging and exception handling tables. This fixes an issue where certain non-identical code objects could be "deduplicated" during compilation.
gh-91146: Reduce allocation size of
list
fromstr.split()
andstr.rsplit()
. Patch by Donghee Na and Inada Naoki.gh-87092: Create a 'jump target label' abstraction in the compiler so that the compiler's codegen stage does not work directly with basic blocks. This prepares the code for changes to the underlying CFG generation mechanism.
gh-95355:
_PyPegen_Parser_New
now properly detects token memory allocation errors. Patch by Honglin Zhu.gh-90081: Run Python code in tracer/profiler function at full speed. Fixes slowdown in earlier versions of 3.11.
gh-95324: Emit a warning in debug mode if an object does not call
PyObject_GC_UnTrack()
before deallocation. Patch by Pablo Galindo.gh-95245: Merge managed dict and values pointer into a single tagged pointer to save one word in the pre-header.
gh-93678: Add cfg_builder struct and refactor the relevant code so that a cfg can be constructed without an instance of the compiler struct.
gh-95185: Prevented crashes in the AST constructor when compiling some absurdly long expressions like
"+0"*1000000
.RecursionError
is now raised instead. Patch by Pablo Galindogh-93351:
ast.AST
node positions are now validated when provided tocompile()
and other related functions. If invalid positions are detected, aValueError
will be raised.gh-94438: Fix an issue that caused extended opcode arguments and some conditional pops to be ignored when calculating valid jump targets for assignments to the
f_lineno
attribute of frame objects. In some cases, this could cause inconsistent internal state, resulting in a hard crash of the interpreter.gh-95060: Undocumented
PyCode_Addr2Location
function now properly returns whenaddrq
argument is less than zero.gh-95113: Replace all
EXTENDED_ARG_QUICK
instructions with basicEXTENDED_ARG
instructions in unquickened code. Consumers of non-adaptive bytecode should be able to handle extended arguments the same way they were handled in CPython 3.10 and older.gh-91409: Fix incorrect source location info caused by certain optimizations in the bytecode compiler.
gh-95023: Implement
os.setns()
andos.unshare()
for Linux. Patch by Noam Cohen.gh-94036: Fix incorrect source location info for some multi-line attribute accesses and method calls.
gh-94938: Fix error detection in some builtin functions when keyword argument name is an instance of a str subclass with overloaded
__eq__
and__hash__
. Previously it could cause SystemError or other undesired behavior.gh-94996:
ast.parse()
will no longer parse function definitions with positional-only params when passedfeature_version
less than(3, 8)
. Patch by Shantanu Jain.gh-94739: Allow jumping within, out of, and across exception handlers in the debugger.
gh-94949:
ast.parse()
will no longer parse parenthesized context managers when passedfeature_version
less than(3, 9)
. Patch by Shantanu Jain.gh-94947:
ast.parse()
will no longer parse assignment expressions when passedfeature_version
less than(3, 8)
. Patch by Shantanu Jain.gh-91256: Ensures the program name is known for help text during interpreter startup.
gh-94869: Fix the column offsets for some expressions in multi-line f-strings
ast
nodes. Patch by Pablo Galindo.gh-94893: Fix an issue where frame object manipulations could corrupt inline bytecode caches.
gh-94822: Fix an issue where lookups of metaclass descriptors may be ignored when an identically-named attribute also exists on the class itself.
gh-91153: Fix an issue where a
bytearray
item assignment could crash if it's resized by the new value's__index__()
method.gh-90699: Fix reference counting bug in
bool.__repr__()
. Patch by Kumar Aditya.gh-94694: Fix an issue that could cause code with multi-line method lookups to have misleading or incorrect column offset information. In some cases (when compiling a hand-built AST) this could have resulted in a hard crash of the interpreter.
gh-93252: Fix an issue that caused internal frames to outlive failed Python function calls, possibly resulting in memory leaks or hard interpreter crashes.
gh-94215: Fix an issue where exceptions raised by line-tracing events would cause frames to be left in an invalid state, possibly resulting in a hard crash of the interpreter.
gh-92228: Disable the compiler's inline-small-exit-blocks optimization for exit blocks that are associated with source code lines. This fixes a bug where the debugger cannot tell where an exception handler ends and the following code block begins.
gh-94485: Line number of a module's
RESUME
instruction is set to 0 as specified in PEP 626.gh-94438: Account for instructions that can push NULL to the stack when setting line number in a frame. Prevents some (unlikely) crashes.
gh-91719: Reload
opcode
when raisingunknown opcode error
in the interpreter main loop, for C compilers to generate dispatching code independently.gh-94329: Compile and run code with unpacking of extremely large sequences (1000s of elements). Such code failed to compile. It now compiles and runs correctly.
gh-94360: Fixed a tokenizer crash when reading encoded files with syntax errors from
stdin
with non utf-8 encoded text. Patch by Pablo Galindogh-88116: Fix an issue when reading line numbers from code objects if the encoded line numbers are close to
INT_MIN
. Patch by Pablo Galindogh-94262: Don't create frame objects for incomplete frames. Prevents the creation of generators and closures from being observable to Python and C extensions, restoring the behavior of 3.10 and earlier.
gh-94192: Fix error for dictionary literals with invalid expression as value.
gh-87995:
types.MappingProxyType
instances are now hashable if the underlying mapping is hashable.gh-93883: Revise the display strategy of traceback enhanced error locations. The indicators are only shown when the location doesn't span the whole line.
gh-94163: Add
BINARY_SLICE
andSTORE_SLICE
instructions for more efficient handling and better specialization of slicing operations, where the slice is explicit in the source code.gh-94021: Fix unreachable code warning in
Python/specialize.c
.gh-93911: Specialize
LOAD_ATTR
for objects with custom__getattribute__
.gh-93955: Improve performance of attribute lookups on objects with custom
__getattribute__
and__getattr__
. Patch by Ken Jin.gh-93911: Specialize
LOAD_ATTR
forproperty()
attributes.gh-93678: Refactor compiler optimisation code so that it no longer needs the
struct assembler
andstruct compiler
passed around. Instead, each function takes the CFG and other data that it actually needs. This will make it possible to test this code directly.gh-93841: When built with
-enable-pystats
,sys._stats_on()
,sys._stats_off()
,sys._stats_clear()
andsys._stats_dump()
functions have been added to enable gathering stats for parts of programs.gh-93516: Store offset of first traceable instruction in code object to avoid having to recompute it for each instruction when tracing.
gh-93516: Lazily create a table mapping bytecode offsets to line numbers to speed up calculation of line numbers when tracing.
gh-89828:
types.GenericAlias
no longer relays the__class__
attribute. For example,isinstance(list[int], type)
no longer returnsTrue
.gh-93678: Refactor the compiler to reduce boilerplate and repetition.
gh-93671: Fix some exponential backtrace case happening with deeply nested sequence patterns in match statements. Patch by Pablo Galindo
gh-93662: Make sure that the end column offsets are correct in multi-line method calls. Previously, the end column could precede the column offset.
gh-93461:
importlib.invalidate_caches()
now drops entries fromsys.path_importer_cache
with a relative path as name. This solves a caching issue when a process changes its current working directory.FileFinder
no longer inserts a dot in the path, e.g./egg/./spam
is now/egg/spam
.gh-93621: Change order of bytecode instructions emitted for
with
andasync with
to reduce the number of entries in the exception table.gh-93533: Reduce the size of the inline cache for
LOAD_METHOD
by 2 bytes.gh-93444: Removed redundant fields from the compiler's basicblock struct:
b_nofallthrough
,b_exit
,b_return
. They can be easily calculated from the opcode of the last instruction of the block.gh-93429:
LOAD_METHOD
instruction has been removed. It was merged back intoLOAD_ATTR
.gh-93418: Fixed an assert where an f-string has an equal sign '=' following an expression, but there's no trailing brace. For example, f"{i=".
gh-93382: Cache the result of
PyCode_GetCode()
function to restore the O(1) lookup of theco_code
attribute.gh-93359: Ensure that custom
ast
nodes without explicit end positions can be compiled. Patch by Pablo Galindo.gh-93356: Code for exception handlers is emitted at the end of the code unit's bytecode. This avoids one jump when no exception is raised.
gh-93354: Use exponential backoff for specialization counters in the interpreter. Can reduce the number of failed specializations significantly and avoid slowdown for those parts of a program that are not suitable for specialization.
gh-93283: Improve error message for invalid syntax of conversion character in f-string expressions.
gh-93345: Fix a crash in substitution of a
TypeVar
in nested generic alias afterTypeVarTuple
.gh-93223: When a bytecode instruction jumps to an unconditional jump instruction, the first instruction can often be optimized to target the unconditional jump's target directly. For tracing reasons, this would previously only occur if both instructions have the same line number. This also now occurs if the unconditional jump is artificial, i.e., if it has no associated line number.
gh-84694: The
--experimental-isolated-subinterpreters
configure option andEXPERIMENTAL_ISOLATED_SUBINTERPRETERS
macro have been removed.gh-91924: Fix
__lltrace__
debug feature if the stdout encoding is not UTF-8. Patch by Victor Stinner.gh-93040: Wraps unused parameters in
Objects/obmalloc.c
withPy_UNUSED
.gh-93143: Avoid
NULL
checks for uninitialized local variables by determining at compile time which variables must be initialized.gh-93061: Backward jumps after
async for
loops are no longer given dubious line numbers.gh-93065: Fix contextvars HAMT implementation to handle iteration over deep trees.
The bug was discovered and fixed by Eli Libman. See MagicStack/immutables#84 for more details.
gh-93012: Added the new function
PyType_FromMetaclass()
, which generalizes the existingPyType_FromModuleAndSpec()
using an additional metaclass argument. This is useful for language binding tools, where it can be used to intercept type-related operations like subclassing or static attribute access by specifying a metaclass with custom slots.Importantly,
PyType_FromMetaclass()
is available in the Limited API, which provides a path towards migrating more binding tools onto the Stable ABI.gh-93021: Fix the
__text_signature__
for__get__()
methods implemented in C. Patch by Jelle Zijlstra.gh-89914: The operand of the
YIELD_VALUE
instruction is set to the stack depth. This is done to help frame handling onyield
and may assist debuggers.gh-92955: Fix memory leak in code object's lines and positions iterators as they were not finalized at exit. Patch by Kumar Aditya.
gh-92930: Fixed a crash in
_pickle.c
from mutating collections during__reduce__
orpersistent_id
.gh-90690: The PRECALL instruction has been removed. It offered only a small advantage for specialization and is not needed in the vast majority of cases.
gh-92914: Always round the allocated size for lists up to the nearest even number.
gh-92858: Improve error message for some suites with syntax error before ':'
gh-90473: Decrease default recursion limit on WASI to address limited call stack size.
gh-92804: Fix memory leak in
memoryview
iterator as it was not finalized at exit. Patch by Kumar Aditya.gh-92777: Specialize
LOAD_METHOD
for objects with lazy dictionaries. Patch by Ken Jin.gh-92658: Add support for connecting and binding to Hyper-V sockets on Windows Hyper-V hosts and guests.
gh-92236: Remove spurious "LINE" event when starting a generator or coroutine, visible tracing functions implemented in C.
gh-91102:
_warnings.warn_explicit()
is ported to Argument Clinic.gh-92619: Make the compiler duplicate an exit block only if none of its instructions have a lineno (previously only the first instruction in the block was checked, leading to unnecessarily duplicated blocks).
gh-88750: The deprecated debug build only
PYTHONTHREADDEBUG
environment variable no longer does anything.gh-92261: Fix hang when trying to iterate over a
typing.Union
.gh-91432: Specialized the
FOR_ITER
opcode using the PEP 659 machinerygh-91399: Removed duplicate '{0, 0, 0, 0, 0, 0}' entry in 'Objects/unicodetype_db.h'.
gh-91578: Updates the error message for abstract class.
bpo-47091: Improve performance of repetition of
list
andtuple
by usingmemcpy
to copy data and performing the reference increments in one step.bpo-46142: Make
--help
output shorter by moving some info to the new--help-env
and--help-xoptions
command-line options. Also add--help-all
option to print complete usage.bpo-42316: Document some places where an assignment expression needs parentheses.
Library¶
gh-89237: Fix hang on Windows in
subprocess.wait_closed()
inasyncio
withProactorEventLoop
. Patch by Kumar Aditya.gh-97928:
tkinter.Text.count()
raises now an exception for options starting with "-" instead of silently ignoring them.gh-98393: The
os
module no longer accepts bytes-like paths, likebytearray
andmemoryview
types: only the exactbytes
type is accepted for bytes strings. Patch by Victor Stinner.gh-98363: Added itertools.batched() to batch data into lists of a given length with the last list possibly being shorter than the others.
gh-98331: Update the bundled copies of pip and setuptools to versions 22.3 and 65.5.0 respectively.
gh-98307: A
createSocket()
method was added toSysLogHandler
.gh-96035: Fix bug in
urllib.parse.urlparse()
that causes certain port numbers containing whitespace, underscores, plus and minus signs, or non-ASCII digits to be incorrectly accepted.gh-98257: Make
sys.setprofile()
andsys.settrace()
functions reentrant. They can no long fail with:RuntimeError("Cannot install a trace function while another trace function is being installed")
. Patch by Victor Stinner.gh-98251: Allow
venv
to pass alongPYTHON*
variables toensurepip
andpip
when they do not impact path resolutiongh-94597: Deprecated
asyncio.AbstractEventLoopPolicy.get_child_watcher()
andasyncio.AbstractEventLoopPolicy.set_child_watcher()
methods to be removed in Python 3.14. Patch by Kumar Aditya.gh-98178: On macOS, fix a crash in
syslog.syslog()
in multi-threaded applications. On macOS, the libcsyslog()
function is not thread-safe, sosyslog.syslog()
no longer releases the GIL to call it. Patch by Victor Stinner.gh-44098: Release the GIL when creating
mmap.mmap
objects on Unix.gh-87730: Wrap network errors consistently in urllib FTP support, so the test suite doesn't fail when a network is available but the public internet is not reachable.
gh-94597: The child watcher classes
MultiLoopChildWatcher
,FastChildWatcher
andSafeChildWatcher
are deprecated and will be removed in Python 3.14. Patch by Kumar Aditya.gh-98023: Change default child watcher to
PidfdChildWatcher
on Linux systems which supports it. Patch by Kumar Aditya.gh-90985: Earlier in 3.11 we deprecated
asyncio.Task.cancel("message")
. We realized we were too harsh, and have undeprecated it.gh-65961: Do not rely solely on
__cached__
on modules; code will also support__spec__.cached
.gh-97646: Replace deprecated
application/javascript
withtext/javascript
inmimetypes
. See RFC 9239. Patch by Noam Cohen.gh-97930: Apply changes from importlib_resources 5.8 and 5.9:
Traversable.joinpath
provides a concrete implementation.as_file
now supports directories of resources.gh-97850: Remove deprecated
importlib.util.set_loader()
andimportlib.util.module_for_loader()
fromimportlib.util
.gh-97837: Change deprecate warning message in
unittest
fromIt is deprecated to return a value!=None
to
It is deprecated to return a value that is not None from a test case
gh-97825: Fixes
AttributeError
whensubprocess.check_output()
is used with argumentinput=None
and either of the arguments encoding or errors are used.gh-97008:
NameError
andAttributeError
spelling suggestions provided since gh-82711 are now also emitted by the pure Pythontraceback
module. Tests for those suggestions now exercise both implementations to ensure they are equivalent. Patch by Carl Friedrich Bolz-Tereick and Łukasz Langa.gh-97799:
dataclass
now usesinspect.get_annotations()
to examine the annotations on class objects.gh-97781: Removed deprecated interfaces in
importlib.metadata
(entry points accessed as dictionary, implicit dictionary construction of sequence ofEntryPoint
objects, mutablility ofEntryPoints
result, access of entry point by index).entry_points
now has a simpler, more straightforward API (returningEntryPoints
).gh-96827: Avoid spurious tracebacks from
asyncio
when default executor cleanup is delayed until after the event loop is closed (e.g. as the result of a keyboard interrupt).gh-95534:
gzip.GzipFile.read()
reads 10% faster.gh-97592: Avoid a crash in the C version of
asyncio.Future.remove_done_callback()
when an evil argument is passed.gh-97545: Make Semaphore run faster.
gh-73588: Fix generation of the default name of
tkinter.Checkbutton
. Previously, checkbuttons in different parent widgets could have the same short name and share the same state if arguments "name" and "variable" are not specified. Now they are globally unique.gh-96865: fix Flag to use boundary CONFORM
This restores previous Flag behavior of allowing flags with non-sequential values to be combined; e.g.
class Skip(Flag): TWO = 2 EIGHT = 8
Skip.TWO | Skip.EIGHT -> <Skip.TWO|EIGHT: 10>
gh-97005: Update bundled libexpat to 2.4.9
gh-85760: Fix race condition in
asyncio
whereprocess_exited()
called before thepipe_data_received()
leading to inconsistent output. Patch by Kumar Aditya.gh-96704: Pass the correct
contextvars.Context
when aasyncio
exception handler is called on behalf of a task or callback handle. This adds a newTask
method,get_context
, and also a newHandle
method with the same name. If this method is not found on a task object (perhaps because it is a third-party library that does not yet provide this method), the context prevailing at the time the exception handler is called is used.gh-96819: Fixed check in
multiprocessing.resource_tracker
that guarantees that the length of a write to a pipe is not greater thanPIPE_BUF
.gh-95865: Reduce
urllib.parse.quote_from_bytes()
memory use on large values.Contributed by Dennis Sweeney.
gh-96741: Corrected type annotation for dataclass attribute
pstats.FunctionProfile.ncalls
to bestr
.gh-96734: Update
unicodedata
database to Unicode 15.0.0.gh-96735: Fix undefined behaviour in
struct.unpack()
.gh-46412: Improve performance of
bool(db)
for large ndb/gdb databases. Previously this would calllen(db)
which would iterate over all keys -- the answer (empty or not) is known after the first key.gh-96652: Fix the faulthandler implementation of
faulthandler.register(signal, chain=True)
if thesigaction()
function is not available: don't call the previous signal handler if it's NULL. Patch by Victor Stinner.gh-68163: Correct conversion of
numbers.Rational
's tofloat
.gh-96538: Speed up
bisect.bisect()
functions by taking advantage of type-stability.gh-96465: Fraction hashes are now cached.
gh-96079: In
typing
, fix missing fieldname
and incorrect__module__
in _AnnotatedAlias.gh-96415: Remove
types._cell_factory
from module namespace.gh-95987: Fix
repr
ofAny
subclasses.gh-96388: Work around missing socket functions in
socket
's__repr__
.gh-96385: Fix
TypeVarTuple.__typing_prepare_subst__
.TypeError
was not raised when using more than oneTypeVarTuple
, like[*T, *V]
in type alias substitutions.gh-96142: Add
match_args
,kw_only
,slots
, andweakref_slot
to_DataclassParams
.gh-96073: In
inspect
, fix overeager replacement of "typing.
" in formatting annotations.gh-89258: Added a
getChildren()
method tologging.Logger
, to get the immediate child loggers of a logger.gh-96346: Use double caching for compiled RE patterns.
gh-96349: Fixed a minor performance regression in
threading.Event.__init__()
gh-90467: Fix
asyncio.streams.StreamReaderProtocol
to keep a strong reference to the created task, so that it's not garbage collectedgh-96172: Fix a bug in
unicodedata
:east_asian_width
used to return the wrong value for unassigned characters; and for yet unassigned, but reserved characters.gh-96159: Fix a performance regression in logging TimedRotatingFileHandler. Only check for special files when the rollover time has passed.
gh-96175: Fix unused
localName
parameter in theAttr
class inxml.dom.minidom
.gh-96145: Add AttrDict to JSON module for use with object_hook.
gh-96052: Fix handling compiler warnings (SyntaxWarning and DeprecationWarning) in
codeop.compile_command()
when checking for incomplete input. Previously it emitted warnings and raised a SyntaxError. Now it always returnsNone
for incomplete input without emitting any warnings.gh-96125: Fix incorrect condition that causes
sys.thread_info.name
to be wrong on pthread platforms.gh-96019: Fix a bug in the
makeunicodedata.py
script leading to about 13 KiB of space saving in theunicodedata
module, specifically the character decomposition data.gh-95463: Remove an incompatible change from bpo-28080 that caused a regression that ignored the utf8 in
ZipInfo.flag_bits
. Patch by Pablo Galindo.gh-69142: Add
%:z
strftime format code (generates tzoffset with colons as separator), see strftime() 和 strptime() 的行为.gh-95899: Fix
asyncio.Runner
to callasyncio.set_event_loop()
only once to avoid callingattach_loop()
multiple times on child watchers. Patch by Kumar Aditya.gh-95736: Fix
unittest.IsolatedAsyncioTestCase
to set event loop before calling setup functions. Patch by Kumar Aditya.gh-95865: Speed up
urllib.parse.quote_from_bytes()
by replacing a list comprehension withmap()
.gh-95861: Add support for computing Spearman's correlation coefficient to the existing statistics.correlation() function.
gh-95804: Fix
logging
shutdown handler so it respectsMemoryHandler.flushOnClose
.gh-95704: When a task catches
asyncio.CancelledError
and raises some other error, the other error should generally not silently be suppressed.gh-95149: The
HTTPStatus
enum offers a couple of properties to indicate the HTTP status category e.g.HTTPStatus.OK.is_success
.gh-95609: Update bundled pip to 22.2.2.
gh-95289: Fix
asyncio.TaskGroup
to propagate exception whenasyncio.CancelledError
was replaced with another exception by a context manger. Patch by Kumar Aditya and Guido van Rossum.gh-94909: Fix incorrect joining of relative Windows paths with drives in
pathlib.PurePath
initializer.gh-95385: Faster
json.dumps()
when sorting of keys is not requested (default).gh-83901: Improve
Signature.bind
error message for missing keyword-only arguments.gh-95339: Update bundled pip to 22.2.1.
gh-95045: Fix GC crash when deallocating
_lsprof.Profiler
by untracking it before calling any callbacks. Patch by Kumar Aditya.gh-95231: Fail gracefully if
EPERM
orENOSYS
is raised when loadingcrypt
methods. This may happen when trying to loadMD5
on a Linux kernel with FIPS enabled.gh-95097: Fix
asyncio.run()
forasyncio.Task
implementations withoutuncancel()
method. Patch by Kumar Aditya.gh-95087: Fix IndexError in parsing invalid date in the
email
module.gh-95199: Upgrade bundled setuptools to 63.2.0.
gh-95194: Upgrade bundled pip to 22.2.
gh-93899: Fix check for existence of
os.EFD_CLOEXEC
,os.EFD_NONBLOCK
andos.EFD_SEMAPHORE
flags on older kernel versions where these flags are not present. Patch by Kumar Aditya.gh-95166: Fix
concurrent.futures.Executor.map()
to cancel the currently waiting on future on an error - e.g. TimeoutError or KeyboardInterrupt.gh-95132: Fix a
sqlite3
regression where*args
and**kwds
were incorrectly relayed fromconnect()
to theConnection
factory. The regression was introduced in 3.11a1 with PR 24421 (gh-85128). Patch by Erlend E. Aasland.`gh-93157: Fix
fileinput
module didn't supporterrors
option wheninplace
is true.gh-91212: Fixed flickering of the turtle window when the tracer is turned off. Patch by Shin-myoung-serp.
gh-95077: Add deprecation warning for enum
member.member
access (e.g.Color.RED.BLUE
). RemoveEnumMeta.__getattr__
.gh-95109: Ensure that timeouts scheduled with
asyncio.Timeout
that have already expired are delivered promptly.gh-95105:
wsgiref.types.InputStream.__iter__()
should returnIterator[bytes]
, notIterable[bytes]
. Patch by Shantanu Jain.gh-95066: Replaced assert with exception in
ast.parse()
, whenfeature_version
has an invalid major version. Patch by Shantanu Jain.gh-77617: Add
sqlite3
command-line interface. Patch by Erlend Aasland.gh-95005: Replace _PyAccu with _PyUnicodeWriter in JSON encoder and StringIO and remove the _PyAccu implementation.
gh-90085: Remove
-c/--clock
and-t/--time
CLI options oftimeit
. The options had been deprecated since Python 3.3 and the functionality was removed in Python 3.7. Patch by Shantanu Jain.gh-94857: Fix refleak in
_io.TextIOWrapper.reconfigure
. Patch by Kumar Aditya.gh-94821: Fix binding of unix socket to empty address on Linux to use an available address from the abstract namespace, instead of "0".
gh-94736: Fix crash when deallocating an instance of a subclass of
_multiprocessing.SemLock
. Patch by Kumar Aditya.gh-81620: Add random.binomialvariate().
gh-74116: Allow
asyncio.StreamWriter.drain()
to be awaited concurrently by multiple tasks. Patch by Kumar Aditya.gh-87822: When called with
capture_locals=True
, thetraceback
module functions swallow exceptions raised from calls torepr()
on local variables of frames. This is in order to prioritize the original exception over rendering errors. An indication of the failure is printed in place of the missing value. (Patch by Simon-Martin Schroeder).gh-88050: Fix
asyncio
subprocess transport to kill process cleanly when process is blocked and avoidRuntimeError
when loop is closed. Patch by Kumar Aditya.gh-94637:
SSLContext.set_default_verify_paths()
now releases the GIL aroundSSL_CTX_set_default_verify_paths
call. The function call performs I/O and CPU intensive work.gh-94309: Deprecate aliases
typing.Hashable
andtyping.Sized
gh-92546: An undocumented
python -m pprint
benchmark is moved intopprint
suite of pyperformance. Patch by Oleg Iarygin.gh-94607: Fix subclassing complex generics with type variables in
typing
. Previously an error message sayingSome type variables ... are not listed in Generic[...]
was shown.typing
no longer populates__parameters__
with the__parameters__
of a Python class.gh-94619: Remove the long-deprecated
module_repr()
fromimportlib
.gh-93910: The ability to access the other values of an enum on an enum (e.g.
Color.RED.BLUE
) has been restored in order to fix a performance regression.gh-93896: Fix
asyncio.run()
andunittest.IsolatedAsyncioTestCase
to always the set event loop as it was done in Python 3.10 and earlier. Patch by Kumar Aditya.gh-94343: Allow setting the attributes of
reprlib.Repr
during object initializationgh-94382: Port static types of
_multiprocessing
module to heap types. Patch by Kumar Aditya.gh-78724: Fix crash in
struct.Struct
when it was not completely initialized by initializing it in__new__`()
. Patch by Kumar Aditya.gh-94510: Re-entrant calls to
sys.setprofile()
andsys.settrace()
now raiseRuntimeError
. Patch by Pablo Galindo.gh-92336: Fix bug where
linecache.getline()
fails on bad files withUnicodeDecodeError
orSyntaxError
. It now returns an empty string as per the documentation.gh-94398: Once a
asyncio.TaskGroup
has started shutting down (i.e., at least one task has failed and the task group has started cancelling the remaining tasks), it should not be possible to add new tasks to the task group.gh-94383:
xml.etree
: Remove theElementTree.Element.copy()
method of the pure Python implementation, deprecated in Python 3.10, use thecopy.copy()
function instead. The C implementation ofxml.etree
has nocopy()
method, only a__copy__()
method. Patch by Victor Stinner.gh-94379:
zipimport
: Removefind_loader()
andfind_module()
methods, deprecated in Python 3.10: use thefind_spec()
method instead. See PEP 451 for the rationale. Patch by Victor Stinner.gh-94352:
shlex.split()
: PassingNone
for s argument now raises an exception, rather than readingsys.stdin
. The feature was deprecated in Python 3.9. Patch by Victor Stinner.gh-89988: Fix memory leak in
pickle.Pickler
when looking updispatch_table
. Patch by Kumar Aditya.gh-90016: Deprecate
sqlite3
default adapters and converters. Patch by Erlend E. Aasland.gh-94254: Fixed types of
struct
module to be immutable. Patch by Kumar Aditya.gh-93259: Now raise
ValueError
whenNone
or an empty string are passed toDistribution.from_name
(and other callers).gh-74696:
shutil.make_archive()
now passes the root_dir argument to custom archivers which support it.gh-94216: The
dis
module now has the opcodes for pseudo instructions (those which are used by the compiler during code generation but then removed or replaced by real opcodes before the final bytecode is emitted).gh-93096: Removed undocumented
python -m codecs
. Usepython -m unittest test.test_codecs.EncodedFileTest
instead.gh-94207: Made
_struct.Struct
GC-tracked in order to fix a reference leak in the_struct
module.gh-93096: Removed undocumented
-t
argument ofpython -m base64
. Usepython -m unittest test.test_base64.LegacyBase64TestCase.test_encodebytes
instead.gh-94226: Remove the
locale.format()
function, deprecated in Python 3.7: uselocale.format_string()
instead. Patch by Victor Stinner.gh-94199: Remove the
ssl.match_hostname()
function. Thessl.match_hostname()
was deprecated in Python 3.7. OpenSSL performs hostname matching since Python 3.7, Python no longer uses thessl.match_hostname()
function. Patch by Victor Stinner.gh-94214: Document the
context
object used in thevenv.EnvBuilder
class, and add the new environment's library path to it.gh-94199: Remove the
ssl.wrap_socket()
function, deprecated in Python 3.7: instead, create assl.SSLContext
object and call itsssl.SSLContext.wrap_socket
method. Any package that still usesssl.wrap_socket()
is broken and insecure. The function neither sends a SNI TLS extension nor validates server hostname. Code is subject to CWE-295: Improper Certificate Validation. Patch by Victor Stinner.gh-94199: Remove the
ssl.RAND_pseudo_bytes()
function, deprecated in Python 3.6: useos.urandom()
orssl.RAND_bytes()
instead. Patch by Victor Stinner.gh-94199:
hashlib
: Remove the pure Python implementation ofhashlib.pbkdf2_hmac()
, deprecated in Python 3.10. Python 3.10 and newer requires OpenSSL 1.1.1 (PEP 644): this OpenSSL version provides a C implementation ofpbkdf2_hmac()
which is faster. Patch by Victor Stinner.gh-94196:
gzip
: Remove thefilename
attribute ofgzip.GzipFile
, deprecated since Python 2.6, use thename
attribute instead. In write mode, thefilename
attribute added'.gz'
file extension if it was not present. Patch by Victor Stinner.gh-94182: run the
asyncio.PidfdChildWatcher
on the running loop, this allows event loops to run subprocesses when there is no default event loop running on the main threadgh-94169: Remove
io.OpenWrapper
and_pyio.OpenWrapper
, deprecated in Python 3.10: just useopen()
instead. Theopen()
(io.open()
) function is a built-in function. Since Python 3.10,_pyio.open()
is also a static method. Patch by Victor Stinner.gh-91742: Fix
pdb
crash after jump caused by a null pointer dereference. Patch by Kumar Aditya.gh-94101: Manual instantiation of
ssl.SSLSession
objects is no longer allowed as it lead to misconfigured instances that crashed the interpreter when attributes where accessed on them.gh-84753:
inspect.iscoroutinefunction()
,inspect.isgeneratorfunction()
, andinspect.isasyncgenfunction()
now properly returnTrue
for duck-typed function-like objects like instances ofunittest.mock.AsyncMock
.This makes
inspect.iscoroutinefunction()
consistent with the behavior ofasyncio.iscoroutinefunction()
. Patch by Mehdi ABAAKOUK.gh-94028: Fix a regression in the
sqlite3
where statement objects were not properly cleared and reset after use in cursor iters. The regression was introduced by PR 27884 in Python 3.11a1. Patch by Erlend E. Aasland.gh-93973: Add keyword argument
all_errors
toasyncio.create_connection
so that multiple connection errors can be raised as anExceptionGroup
.gh-93963: Officially deprecate from
importlib.abc
classes moved toimportlib.resources.abc
.gh-93858: Prevent error when activating venv in nested fish instances.
gh-93847: Fix repr of enum of generic aliases.
gh-91404: Revert the
re
memory leak when a match is terminated by a signal or memory allocation failure as the implemented fix caused a major performance regression.gh-83499: Fix double closing of file description in
tempfile
.gh-93820: Fixed a regression when
copy.copy()
-ingenum.Flag
with multiple flag members.gh-79512: Fixed names and
__module__
value ofweakref
classesReferenceType
,ProxyType
,CallableProxyType
. It makes them pickleable.gh-91389: Fix an issue where
dis
utilities could report missing or incorrect position information in the presence ofCACHE
entries.gh-93626: Set
__future__.annotations
to have aNone
mandatoryRelease to indicate that it is currently 'TBD'.gh-90473: Emscripten and WASI have no home directory and cannot provide PEP 370 user site directory.
gh-90494:
copy.copy()
andcopy.deepcopy()
now always raise a TypeError if__reduce__()
returns a tuple with length 6 instead of silently ignore the 6th item or produce incorrect result.gh-90549: Fix a multiprocessing bug where a global named resource (such as a semaphore) could leak when a child process is spawned (as opposed to forked).
gh-93521: Fixed a case where dataclasses would try to add
__weakref__
into the__slots__
for a dataclass that specifiedweakref_slot=True
when it was already defined in one of its bases. This resulted in aTypeError
upon the new class being created.gh-79579:
sqlite3
now correctly detects DML queries with leading comments. Patch by Erlend E. Aasland.gh-93421: Update
sqlite3.Cursor.rowcount
when a DML statement has run to completion. This fixes the row count for SQL queries likeUPDATE ... RETURNING
. Patch by Erlend E. Aasland.gh-93475: Expose
FICLONE
andFICLONERANGE
constants infcntl
. Patch by Illia Volochii.gh-93370: Deprecate
sqlite3.version
andsqlite3.version_info
.gh-91810: Suppress writing an XML declaration in open files in
ElementTree.write()
withencoding='unicode'
andxml_declaration=None
.gh-91162: Support splitting of unpacked arbitrary-length tuple over
TypeVar
andTypeVarTuple
parameters. For example:A[T, *Ts][*tuple[int, ...]]
->A[int, *tuple[int, ...]]
A[*Ts, T][*tuple[int, ...]]
->A[*tuple[int, ...], int]
gh-93353: Fix the
importlib.resources.as_file()
context manager to remove the temporary file if destroyed late during Python finalization: keep a local reference to theos.remove()
function. Patch by Victor Stinner.gh-83658: Make
multiprocessing.Pool
raise an exception ifmaxtasksperchild
is notNone
or a positive int.gh-93312: Add
os.PIDFD_NONBLOCK
flag to open a file descriptor for a process withos.pidfd_open()
in non-blocking mode. Patch by Kumar Aditya.gh-88123: Implement Enum __contains__ that returns True or False to replace the deprecated behaviour that would sometimes raise a TypeError.
gh-93297: Make asyncio task groups prevent child tasks from being GCed
gh-85308: Changed
argparse.ArgumentParser
to use filesystem encoding and error handler instead of default text encoding to read arguments from file (e.g.fromfile_prefix_chars
option). This change affects Windows; argument file should be encoded with UTF-8 instead of ANSI Codepage.gh-93156: Accessing the
pathlib.PurePath.parents
sequence of an absolute path using negative index values produced incorrect results.gh-93162: Add the ability for
logging.config.dictConfig()
to usefully configureQueueHandler
andQueueListener
as a pair, and addlogging.getHandlerByName()
andlogging.getHandlerNames()
APIs to allow access to handlers by name.gh-93243: The
smtpd
module was removed per the schedule in PEP 594.gh-92886: Replace
assert
statements withraise AssertionError()
inBaseHandler
so that the tested behaviour is maintained running with optimizations(-O)
.gh-90155: Fix broken
asyncio.Semaphore
when acquire is cancelled.gh-90817: The
locale.resetlocale()
function is deprecated and will be removed in Python 3.13. Uselocale.setlocale(locale.LC_ALL, "")
instead. Patch by Victor Stinner.gh-91513: Added
taskName
attribute tologging
module for use withasyncio
tasks.gh-74696:
shutil.make_archive()
no longer temporarily changes the current working directory during creation of standard.zip
or tar archives.gh-92728: The
re.template()
function and the correspondingre.TEMPLATE
andre.T
flags are restored after they were removed in 3.11.0b1, but they are now deprecated, so they might be removed from Python 3.13.gh-93033: Search in some strings (platform dependent i.e [U+0xFFFF, U+0x0100] on Windows or [U+0xFFFFFFFF, U+0x00010000] on Linux 64-bit) are now up to 10 times faster.
gh-89973: Fix
re.error
raised infnmatch
if the pattern contains a character range with upper bound lower than lower bound (e.g.[c-a]
). Now such ranges are interpreted as empty ranges.gh-93044: No longer convert the database argument of
sqlite3.connect()
to bytes before passing it to the factory.gh-93010: In a very special case, the email package tried to append the nonexistent
InvalidHeaderError
to the defect list. It should have beenInvalidHeaderDefect
.gh-92986: Fix
ast.unparse()
whenImportFrom.level
is Nonegh-92932: Now
dis()
andget_instructions()
handle operand values for instructions prefixed byEXTENDED_ARG_QUICK
. Patch by Sam Gross and Donghee Na.gh-92675: Fix
venv.ensure_directories()
to acceptpathlib.Path
arguments in addition tostr
paths. Patch by David Foster.gh-87901: Removed the
encoding
argument fromos.popen()
that was added in 3.11b1.gh-91922: Fix function
sqlite.connect()
and thesqlite.Connection
constructor on non-UTF-8 locales. Also, they now support bytes paths non-decodable with the current FS encoding.gh-92869: Added
c_time_t
toctypes
, which has the same size as thetime_t
type in C.gh-92839: Fixed crash resulting from calling bisect.insort() or bisect.insort_left() with the key argument not equal to None.
gh-90473:
subprocess
now fails early on Emscripten and WASI platforms to work around missingos.pipe()
on WASI.gh-89325: Removed many old deprecated
unittest
features:TestCase
method aliases, undocumented and brokenTestCase
methodassertDictContainsSubset
, undocumentedTestLoader.loadTestsFromModule
parameter use_load_tests, and an underscored alias of theTextTestResult
class.gh-92734: Allow multi-element reprs emitted by
reprlib
to be pretty-printed using configurable indentation.gh-92671: Fixed
ast.unparse()
for empty tuples in the assignment target context.gh-91581:
utcfromtimestamp()
no longer attempts to resolvefold
in the pure Python implementation, since the fold is never 1 in UTC. In addition to being slightly faster in the common case, this also prevents some errors when the timestamp is close todatetime.min
. Patch by Paul Ganssle.gh-86388: Removed randrange() functionality deprecated since Python 3.10. Formerly, randrange(10.0) losslessly converted to randrange(10). Now, it raises a TypeError. Also, the exception raised for non-integral values such as randrange(10.5) or randrange('10') has been changed from ValueError to TypeError.
gh-90385: Add
pathlib.Path.walk()
as an alternative toos.walk()
.gh-92550: Fix
pathlib.Path.rglob()
for empty pattern.gh-92591: Allow
logging
filters to return alogging.LogRecord
instance so that filters attached tologging.Handler
s can enrich records without side effects on other handlers.gh-92445: Fix a bug in
argparse
wherenargs="*"
would raise an error instead of returning an empty list when 0 arguments were supplied if choice was also defined inparser.add_argument
.gh-92547: Remove undocumented
sqlite3
features deprecated in Python 3.10:sqlite3.enable_shared_cache()
sqlite3.OptimizedUnicode
Patch by Erlend E. Aasland.
gh-92530: Fix an issue that occurred after interrupting
threading.Condition.notify()
.gh-92531: The statistics.median_grouped() function now always return a float. Formerly, it did not convert the input type when for sequences of length one.
gh-84131: The
pathlib.Path
deprecated methodlink_to
has been removed. Use 3.10'shardlink_to()
method instead as its semantics are consistent with that ofsymlink_to()
.gh-89336: Removed
configparser
module APIs: theSafeConfigParser
class alias, theParsingError.filename
property and parameter, and theConfigParser.readfp
method, all of which were deprecated since Python 3.2.gh-92391: Add
__class_getitem__()
tocsv.DictReader
andcsv.DictWriter
, allowing them to be parameterized at runtime. Patch by Marc Mueller.gh-91968: Add
SO_RTABLE
andSO_USER_COOKIE
constants tosocket
.gh-91810:
ElementTree
methodwrite()
and functiontostring()
now use the text file's encoding ("UTF-8" if not available) instead of locale encoding in XML declaration whenencoding="unicode"
is specified.gh-81790:
os.path.splitdrive()
now understands DOS device paths with UNC links (beginning\\?\UNC\
). Contributed by Barney Gale.gh-91760: Apply more strict rules for numerical group references and group names in regular expressions. Only sequence of ASCII digits is now accepted as a numerical reference. The group name in bytes patterns and replacement strings can now only contain ASCII letters and digits and underscore.
gh-90622: Worker processes for
concurrent.futures.ProcessPoolExecutor
are no longer spawned on demand (a feature added in 3.9) when the multiprocessing context start method is"fork"
as that can lead to deadlocks in the child processes due to a fork happening while threads are running.gh-91577: Move imports in
SharedMemory
methods to module level so that they can be executed late in python finalization.gh-91581: Remove an unhandled error case in the C implementation of calls to
datetime.fromtimestamp
with no time zone (i.e. getting a local time from an epoch timestamp). This should have no user-facing effect other than giving a possibly more accurate error message when called with timestamps that fall on 10000-01-01 in the local time. Patch by Paul Ganssle.gh-91539: Improve performance of
urllib.request.getproxies_environment
when there are many environment variablesgh-91524: Speed up the regular expression substitution (functions
re.sub()
andre.subn()
and correspondingre.Pattern
methods) for replacement strings containing group references by 2--3 times.gh-91447: Fix findtext in the xml module to only give an empty string when the text attribute is set to None.
gh-91456: Deprecate current default auto() behavior: In 3.13 the default will be for for auto() to always return the largest member value incremented by 1, and to raise if incompatible value types are used.
bpo-47231: Fixed an issue with inconsistent trailing slashes in tarfile longname directories.
bpo-39064:
zipfile.ZipFile
now raiseszipfile.BadZipFile
instead ofValueError
when reading a corrupt zip file in which the central directory offset is negative.bpo-41287: Fix handling of the
doc
argument in subclasses ofproperty()
.gh-90005:
ctypes
dependencylibffi
is now detected withpkg-config
.bpo-32547: The constructors for
DictWriter
andDictReader
now coerce thefieldnames
argument to alist
if it is an iterator.bpo-35540: Fix
dataclasses.asdict()
crash whencollections.defaultdict
is present in the attributes.bpo-47063: Add an index_pages parameter to support using non-default index page names.
bpo-46951: Order the contents of zipapp archives, to make builds more reproducible.
bpo-42777: Implement
pathlib.Path.is_mount()
for Windows paths.bpo-46755: In
QueueHandler
, clearstack_info
fromLogRecord
to prevent stack trace from being written twice.bpo-45393: Fix the formatting for
await x
andnot x
in the operator precedence table when using thehelp()
system.bpo-46642: Improve error message when trying to subclass an instance of
typing.TypeVar
,typing.ParamSpec
,typing.TypeVarTuple
, etc. Based on patch by Gregory Beauregard.bpo-46364: Restrict use of sockets instead of pipes for stdin of subprocesses created by
asyncio
to AIX platform only.bpo-28249: Set
doctest.DocTest.lineno
toNone
when object does not have__doc__
.bpo-46197: Fix
ensurepip
environment isolation for subprocess runningpip
.bpo-45924: Fix
asyncio
incorrect traceback when future's exception is raised multiple times. Patch by Kumar Aditya.bpo-45046: Add support of context managers in
unittest
: methodsenterContext()
andenterClassContext()
of classTestCase
, methodenterAsyncContext()
of classIsolatedAsyncioTestCase
and functionunittest.enterModuleContext()
.bpo-44173: Enable fast seeking of uncompressed unencrypted
zipfile.ZipExtFile
bpo-42627: Fix incorrect parsing of Windows registry proxy settings
bpo-42047: Add
threading.get_native_id()
support for DragonFly BSD. Patch by David Carlier.bpo-14243: The
tempfile.NamedTemporaryFile
function has a new optional parameter delete_on_closebpo-41246: Give the same callback function for when the overlapped operation is done to the functions
recv
,recv_into
,recvfrom
,sendto
,send
andsendfile
insideIocpProactor
.bpo-39264: Fixed
collections.UserDict.get()
to not call__missing__()
when a value is not found. This matches the behavior ofdict
. Patch by Bar Harel.bpo-38693:
importlib
now uses f-strings internally instead ofstr.format
.bpo-38267: Add timeout parameter to
asyncio.loop.shutdown_default_executor()
. The default value isNone
, which means the executor will be given an unlimited amount of time. When called fromasyncio.Runner
orasyncio.run()
, the default timeout is 5 minutes.bpo-34828:
sqlite3.Connection.iterdump()
now handles databases that useAUTOINCREMENT
in one or more tables.bpo-32990: Support reading wave files with the
WAVE_FORMAT_EXTENSIBLE
format in thewave
module.bpo-26253: Allow adjustable compression level for tarfile streams in
tarfile.open()
.
Documentation¶
gh-85525: Remove extra row
gh-86404: Deprecated tools
make suspicious
andrstlint.py
are now removed. They have been replaced by spinx-lint.gh-97741: Fix
!
in c domain ref target syntax via aconf.py
patch, so it works as intended to disable ref target resolution.gh-96432: Fraction literals now support whitespace around the forward slash,
Fraction('2 / 3')
.gh-96098: Improve discoverability of the higher level concurrent.futures module by providing clearer links from the lower level threading and multiprocessing modules.
gh-95957: What's New 3.11 now has instructions for how to provide compiler and linker flags for Tcl/Tk and OpenSSL on RHEL 7 and CentOS 7.
gh-95588: Clarified the conflicting advice given in the
ast
documentation aboutast.literal_eval()
being "safe" for use on untrusted input while at the same time warning that it can crash the process. The latter statement is true and is deemed unfixable without a large amount of work unsuitable for a bugfix. So we keep the warning and no longer claim thatliteral_eval
is safe.gh-91207: Fix stylesheet not working in Windows CHM htmlhelp docs and add warning that they are deprecated. Contributed by C.A.M. Gerlach.
gh-95454: Replaced incorrectly written true/false values in documentiation. Patch by Robert O'Shea
gh-95451: Update library documentation with availability information on WebAssembly platforms
wasm32-emscripten
andwasm32-wasi
.gh-95415: Use consistent syntax for platform availability. The directive now supports a content body and emits a warning when it encounters an unknown platform.
gh-94321: Document the PEP 246 style protocol type
sqlite3.PrepareProtocol
.gh-86128: Document a limitation in ThreadPoolExecutor where its exit handler is executed before any handlers in atexit.
gh-61162: Clarify
sqlite3
behavior when 如何使用连接上下文管理器.gh-87260: Align
sqlite3
argument specs with the actual implementation.gh-86986: The minimum Sphinx version required to build the documentation is now 3.2.
gh-88831: Augmented documentation of asyncio.create_task(). Clarified the need to keep strong references to tasks and added a code snippet detailing how to do this.
gh-86438: Clarify that
-W
andPYTHONWARNINGS
are matched literally and case-insensitively, rather than as regular expressions, inwarnings
.gh-93031: Update tutorial introduction output to use 3.10+ SyntaxError invalid range.
gh-92240: Added release dates for "What's New in Python 3.X" for 3.0, 3.1, 3.2, 3.8 and 3.10
bpo-47161: Document that
pathlib.PurePath
does not collapse initial double slashes because they denote UNC paths.bpo-40838: Document that
inspect.getdoc()
,inspect.getmodule()
, andinspect.getsourcefile()
might returnNone
.bpo-43689: The
Differ
documentation now also mentions other whitespace characters, which make it harder to understand the diff output.bpo-13553: Document tkinter.Tk args.
Tests¶
gh-95027: On Windows, when the Python test suite is run with the
-jN
option, the ANSI code page is now used as the encoding for the stdout temporary file, rather than using UTF-8 which can lead to decoding errors. Patch by Victor Stinner.gh-96624: Fixed the failure of repeated runs of
test.test_unittest
caused by side effects intest_dotted_but_module_not_loaded
.gh-95243: Mitigate the inherent race condition from using find_unused_port() in testSockName() by trying to find an unused port a few times before failing. Patch by Ross Burton.
gh-95573: Lib/test/test_asyncio/test_ssl.py exposed a bug in the macOS kernel where intense concurrent load on non-blocking sockets occasionally causes
errno.ENOBUFS
("No buffer space available") to be emitted. FB11063974 filed with Apple, in the mean time as a workaround buffer size used in tests on macOS is decreased to avoid intermittent failures. Patch by Fantix King.gh-95280: Fix problem with
test_ssl
test_get_ciphers
on systems that require perfect forward secrecy (PFS) ciphers.gh-95212: Make multiprocessing test case
test_shared_memory_recreate
parallel-safe.gh-95218: Move tests for importlib.resources into test_importlib.resources.
gh-93963: Updated tests to use preferred location for
importlib.resources
ABCs.gh-94675: Add a regression test for
re
exponentional slowdown when using rjsmin.gh-91330: Added more tests for
dataclasses
to cover behavior with data descriptor-based fields.gh-94208:
test_ssl
is now checking for supported TLS version and protocols in more tests.gh-94315: Tests now check for DAC override capability instead of relying on
os.geteuid()
.gh-54781: Rename test_tk to test_tkinter, and rename test_ttk_guionly to test_ttk. Patch by Victor Stinner.
gh-93839: Move
Lib/ctypes/test/
toLib/test/test_ctypes/
. Patch by Victor Stinner.gh-93951: In test_bdb.StateTestCase.test_skip, avoid including auxiliary importers.
gh-93957: Provide nicer error reporting from subprocesses in test_venv.EnsurePipTest.test_with_pip.
gh-93884: Add test cases for
PyNumber_ToBase()
that take a large number or a non-int object as parameter.gh-93852: test_asyncio, test_logging, test_socket and test_socketserver now create AF_UNIX domains in the current directory to no longer fail with
OSError("AF_UNIX path too long")
if the temporary directory (theTMPDIR
environment variable) is too long. Patch by Victor Stinner.gh-93353: regrtest now checks if a test leaks temporary files or directories if run with -jN option. Patch by Victor Stinner.
gh-84461:
run_tests.py
now handles cross compiling env vars correctly and passHOSTRUNNER
to regression tests.gh-93616:
test_modulefinder
now creates a temporary directory inModuleFinderTest.setUp()
instead of module scope.gh-93575: Fix issue with test_unicode test_raiseMemError. The test case now use
test.support.calcobjsize
to calculate size of PyUnicode structs.sys.getsizeof()
may return different size when string has UTF-8 memory.gh-90473: WASI does not have a
chmod(2)
syscall.os.chmod()
is now a dummy function on WASI. Skip all tests that depend on workingos.chmod()
.gh-90473: Skip tests on WASI that require symlinks with absolute paths.
gh-57539: Increase calendar test coverage for
calendar.LocaleTextCalendar.formatweekday()
.gh-90473: Skip symlink tests on WASI. wasmtime uses
openat2(2)
withRESOLVE_BENEATH
flag, which prevents symlinks with absolute paths.gh-89858: Fix
test_embed
for out-of-tree builds. Patch by Kumar Aditya.gh-92886: Fixing tests that fail when running with optimizations (
-O
) intest_imaplib.py
.gh-92886: Fixing tests that fail when running with optimizations (
-O
) intest_zipimport.py
gh-92886: Fixing tests that fail when running with optimizations (
-O
) intest_py_compile.py
gh-92886: Fixing tests that fail when running with optimizations (
-O
) intest_sys_settrace.py
.gh-92886: Fixing tests that fail when running with optimizations (
-O
) in_test_multiprocessing.py
gh-92670: Skip
test_shutil.TestCopy.test_copyfile_nonexistent_dir
test on AIX as the test uses a trailing slash to force the OS consider the path as a directory, but on AIX the trailing slash has no effect and is considered as a file.gh-92514: Remove unused
test.support.BasicTestRunner
. Patch by Jelle Zijlstra.bpo-47016: Create a GitHub Actions workflow for verifying bundled pip and setuptools. Patch by Illia Volochii and Adam Turner.
Build¶
gh-96761: Fix the build process of clang compiler for _bootstrap_python if LTO optimization is applied. Patch by Matthias Görgens and Donghee Na.
gh-96883:
wasm32-emscripten
builds for browsers now includeconcurrent.futures
forasyncio
andunittest.mock
.gh-85936: CPython now uses the ThinLTO option as the default policy if the Clang compiler accepts the flag. Patch by Donghee Na.
gh-96729: Ensure that Windows releases built with
Tools\msi\buildrelease.bat
are upgradable to and from official Python releases.gh-96269: Shared module targets now depend on new
MODULE_DEPS
variable, which includesEXPORTSYMS
. This fixes a build order issue on unsupported AIX platform.gh-84461:
wasm32-emscripten
platform no longer buildsresource
module,getresuid()
,getresgid()
, and their setters. The APIs are stubs and not functional.gh-95973: Add a new
--with-dsymutil
configure option to link debug information in macOS. Patch by Pablo Galindo.gh-90536: Use the BOLT post-link optimizer to improve performance, particularly on medium-to-large applications.
gh-93744: Remove the
configure --with-cxx-main
build option: it didn't work for many years. Remove theMAINCC
variable fromconfigure
andMakefile
. Patch by Victor Stinner.gh-94801: Fix a regression in
configure
script that caused some header checks to ignore customCPPFLAGS
. The regression was introduced in gh-94802.gh-95145: wasm32-wasi builds no longer depend on WASIX's pthread stubs. Python now has its own stubbed pthread API.
gh-95174: Python now detects missing
dup
function in WASI and works around some missingerrno
,select
, andsocket
constants.gh-95174: Python now skips missing
socket
functions and methods on WASI. WASI can only create sockets from existing fd / accept and has no netdb.gh-95085: Platforms
wasm32-unknown-emscripten
andwasm32-unknown-wasi
have been promoted to PEP 11 tier 3 platform support.gh-94847: Fixed
_decimal
module build issue on GCC when compiling with LTO and pydebug. Debug builds no longer force inlining of functions.gh-94841: Fix the possible performance regression of
PyObject_Free()
compiled with MSVC version 1932.gh-94801:
configure
now uses custom flags likeZLIB_CFLAGS
andZLIB_LIBS
when searching for headers and libraries.gh-94773:
deepfreeze.py
now supports code object with frozensets that contain incompatible, unsortable types.gh-94682: Build and test with OpenSSL 1.1.1q
gh-90005: Dependencies of
readline
andcurses
module are now detected inconfigure
script withpkg-config
. Onlyncurses
/ncursesw
are detected automatically. The oldcurses
library is not configured automatically. Workaround for missingtermcap
ortinfo
library has been removed.gh-90005: Fix building
_ctypes
extension withoutpkg-config
.gh-90005:
_dbm
module dependencies are now detected by configure.gh-94404:
makesetup
now works around an issue with sed on macOS and uses correct CFLAGS for object files that end up in a shared extension. Module CFLAGS are used before PY_STDMODULE_CFLAGS to avoid clashes with system headers.gh-93939: C extension modules are now built by
configure
andmake
instead ofdistutils
andsetup.py
.gh-93939: The
2to3
,idle
, andpydoc
scripts are now generated and installed byMakefile
instead ofsetup.py
.gh-94280: Updated pegen regeneration script on Windows to find and use Python 3.9 or higher. Prior to this, pegen regeneration already required 3.9 or higher, but the script may have used lower versions of Python.
gh-93584: Address race condition in
Makefile
when installing a PGO build. Alltest
andinstall
targets now depend onall
target.gh-93491:
configure
now detects and reports PEP 11 support tiers.gh-69093: Fix
Modules/Setup.stdlib.in
rule for_sqlite3
extension.gh-93207:
va_start()
with two parameters, likeva_start(args, format),
is now required to build Python.va_start()
is no longer called with a single parameter. Patch by Kumar Aditya.gh-93202: Python now always use the
%zu
and%zd
printf formats to format asize_t
orPy_ssize_t
number. Building Python 3.12 requires a C11 compiler, so these printf formats are now always supported. Patch by Victor Stinner.gh-90473: Disable pymalloc and increase stack size on
wasm32-wasi
.bpo-34449: Drop invalid compiler switch
-fPIC
for HP aCC on HP-UX. Patch by Michael Osipov.
Windows¶
gh-98360: Fixes
multiprocessing
spawning child processes on Windows from a virtual environment to ensure that child processes that also usemultiprocessing
to spawn more children will recognize that they are in a virtual environment.gh-98414: Fix
py.exe
launcher handling of-V:<company>/
option when default preferences have been set in environment variables or configuration files.gh-97728: Fix possible crashes caused by the use of uninitialized variables when pass invalid arguments in
os.system()
on Windows and in Windows-specific modules (likewinreg
).gh-90989: Made 适用于Windows的Python启动器 install per-user by default (unless an all users install already exists), and clarify some text in the installer.
gh-97649: The
Tools
directory is no longer installed on Windowsgh-96965: Update libffi to 3.4.3
gh-96559: Fixes the Windows launcher not using the compatible interpretation of default tags found in configuration files when no tag was passed to the command.
gh-94781: Fix
pcbuild.proj
to clean previous instances of output files inPython\deepfreeze
andPython\frozen_modules
directories on Windows. Patch by Charlie Zhao.gh-89545: Updates
platform
code getting the Windows version to use native Windows Management Instrumentation (WMI) queries to determine OS version, type, and architecture.gh-95733: Make certain requirements of the Windows Store package optional to allow installing on earlier updates of Windows.
gh-95656: Enable the
enable_load_extension()
sqlite3
API.gh-95587: Fixes some issues where the Windows installer would incorrectly detect certain features of an existing install when upgrading.
gh-94399: Restores the behaviour of 适用于Windows的Python启动器 for
/usr/bin/env
shebang lines, which will now searchPATH
for an executable matching the given command. If none is found, the usual search process is used.gh-95445: Fixes the unsuccessful removal of the HTML document directory when uninstalling with Windows msi.
gh-95359: Fix 适用于Windows的Python启动器 handling of
py.ini
commands (it was incorrectly expecting apy_
prefix on keys) and crashes when reading per-user configuration file.gh-95285: Fix 适用于Windows的Python启动器 handling of command lines where it is only passed a short executable name.
gh-90844: Allow virtual environments to correctly launch when they have spaces in the path.
gh-94772: Fix incorrect handling of shebang lines in py.exe launcher
gh-94018:
zipfile
will now remove trailing spaces from path components when extracting files on Windows.gh-93824: Drag and drop of files onto Python files in Windows Explorer has been enabled for Windows ARM64.
gh-43414:
os.get_terminal_size()
now attempts to read the size from any provided handle, rather than only supporting file descriptors 0, 1 and 2.gh-92817: Ensures that
py.exe
will prefer an active virtual environment over default tags specified with environment variables or through apy.ini
file.gh-92984: Explicitly disable incremental linking for non-Debug builds
gh-92841:
asyncio
no longer throwsRuntimeError: Event loop is closed
on interpreter exit after asynchronous socket activity. Patch by Oleg Iarygin.bpo-46907: Update Windows installer to use SQLite 3.38.4.
gh-91061: Accept os.PathLike for the argument to winsound.PlaySound
bpo-42658: Support native Windows case-insensitive path comparisons by using
LCMapStringEx
instead ofstr.lower()
inntpath.normcase()
. AddLCMapStringEx
to the_winapi
module.bpo-38704: Prevent installation on unsupported Windows versions.
macOS¶
gh-97897: The macOS 13 SDK includes support for the
mkfifoat
andmknodat
system calls. Using thedir_fd
option with eitheros.mkfifo()
oros.mknod()
could result in a segfault if cpython is built with the macOS 13 SDK but run on an earlier version of macOS. Prevent this by adding runtime support for detection of these system calls ("weaklinking") as is done for other newer syscalls on macOS.
IDLE¶
gh-97527: Fix a bug in the previous bugfix that caused IDLE to not start when run with 3.10.8, 3.12.0a1, and at least Microsoft Python 3.10.2288.0 installed without the Lib/test package. 3.11.0 was never affected.
gh-65802: Document handling of extensions in Save As dialogs.
gh-95191: Include prompts when saving Shell (interactive input and output).
gh-95511: Fix the Shell context menu copy-with-prompts bug of copying an extra line when one selects whole lines.
gh-95471: In the Edit menu, move
Select All
and add a new separator.gh-95411: Enable using IDLE's module browser with .pyw files.
gh-89610: Add .pyi as a recognized extension for IDLE on macOS. This allows opening stub files by double clicking on them in the Finder.
Tools/Demos¶
gh-68686: Remove ptags and eptags scripts.
gh-97681: Remove the
Tools/demo/
directory which contained old demo scripts. A copy can be found in the old-demos project. Patch by Victor Stinner.gh-97669: Remove outdated example scripts of the
Tools/scripts/
directory. A copy can be found in the old-demos project. Patch by Victor Stinner.gh-95853: The
wasm_build.py
script now pre-builds Emscripten ports, checks for broken EMSDK versions, and warns about pkg-config env vars.gh-95853: The new tool
Tools/wasm/wasm_builder.py
automates configure, compile, and test steps for building CPython on WebAssembly platforms.gh-95731: Fix handling of module docstrings in
Tools/i18n/pygettext.py
.gh-93939: Add script
Tools/scripts/check_modules.py
to check and validate builtin and shared extension modules. The script also handlesModules/Setup
and will eventually replacesetup.py
.gh-94538: Fix Argument Clinic output to custom file destinations. Patch by Erlend E. Aasland.
gh-94430: Allow parameters named
module
andself
with custom C names in Argument Clinic. Patch by Erlend E. Aaslandgh-86087: The
Tools/scripts/parseentities.py
script used to parse HTML4 entities has been removed.
C API¶
gh-98393: The
PyUnicode_FSDecoder()
function no longer accepts bytes-like paths, likebytearray
andmemoryview
types: only the exactbytes
type is accepted for bytes strings. Patch by Victor Stinner.gh-91051: Add
PyType_Watch()
and related APIs to allow callbacks onPyType_Modified()
.gh-95756: Lazily create and cache
co_
attributes for better performance for code getters.gh-96512: Configuration for the integer string conversion length limitation now lives in the PyConfig C API struct.
gh-95589: Extensions classes that set
tp_dictoffset
andtp_weaklistoffset
lose the support for multiple inheritance, but are now safe. Extension classes should usePy_TPFLAGS_MANAGED_DICT
andPy_TPFLAGS_MANAGED_WEAKREF
instead.gh-95781: An unrecognized format character in
PyUnicode_FromFormat()
andPyUnicode_FromFormatV()
now sets aSystemError
. In previous versions it caused all the rest of the format string to be copied as-is to the result string, and any extra arguments discarded.gh-92678: Restore the 3.10 behavior for multiple inheritance of C extension classes that store their dictionary at the end of the struct.
gh-92678: Support C extensions using managed dictionaries by setting the
Py_TPFLAGS_MANAGED_DICT
flag.gh-93274: API for implementing vectorcall (
Py_TPFLAGS_HAVE_VECTORCALL
,PyVectorcall_NARGS()
andPyVectorcall_Call()
) was added to the limited API and stable ABI.gh-95504: Fix sign placement when specifying width or precision in
PyUnicode_FromFormat()
andPyUnicode_FromFormatV()
. Patch by Philip Georgi.gh-93012: The
Py_TPFLAGS_HAVE_VECTORCALL
flag is now removed from a class when the class's__call__()
method is reassigned. This makes vectorcall safe to use with mutable types (i.e. heap types without theimmutable
flag). Mutable types that do not overridetp_call
now inherit thePy_TPFLAGS_HAVE_VECTORCALL
flag.gh-95388: Creating
immutable types
with mutable bases is deprecated and is planned to be disabled in Python 3.14.gh-92678: Adds unstable C-API functions
_PyObject_VisitManagedDict
and_PyObject_ClearManagedDict
to allow C extensions to allow the VM to manage their object's dictionaries.gh-94936: Added
PyCode_GetVarnames()
,PyCode_GetCellvars()
andPyCode_GetFreevars()
for accessingco_varnames
,co_cellvars
andco_freevars
respectively via the C API.gh-94930: Fix
SystemError
raised whenPyArg_ParseTupleAndKeywords()
is used with#
in(...)
but withoutPY_SSIZE_T_CLEAN
defined.gh-94731: Python again uses C-style casts for most casting operations when compiled with C++. This may trigger compiler warnings, if they are enabled with e.g.
-Wold-style-cast
or-Wzero-as-null-pointer-constant
options forg++
.gh-93937: The following frame functions and type are now directly available with
#include <Python.h>
, it's no longer needed to add#include <frameobject.h>
:Patch by Victor Stinner.
gh-91321: Fix the compatibility of the Python C API with C++ older than C++11. Patch by Victor Stinner.
gh-91731: Avoid defining the
static_assert
when compiling with C++ 11, where this is a keyword and redefining it can lead to undefined behavior. Patch by Pablo Galindogh-89546:
PyType_FromMetaclass()
(and otherPyType_From*
functions) now check that offsets and the base class'stp_basicsize
fit in the new class'stp_basicsize
.gh-93503: Add two new public functions to the public C-API,
PyEval_SetProfileAllThreads()
andPyEval_SetTraceAllThreads()
, that allow to set tracing and profiling functions in all running threads in addition to the calling one. Also, two analogous functions to thethreading
module (threading.setprofile_all_threads()
andthreading.settrace_all_threads()
) that allow to do the same from Python. Patch by Pablo Galindogh-93442: Add C++ overloads for _Py_CAST_impl() to handle 0/NULL. This will allow C++ extensions that pass 0 or NULL to macros using _Py_CAST() to continue to compile.
gh-93466: Slot IDs in PyType_Spec may not be repeated. The documentation was updated to mention this. For some cases of repeated slots, PyType_FromSpec and related functions will now raise an exception.
gh-92898: Fix C++ compiler warnings when casting function arguments to
PyObject*
. Patch by Serge Guelton.gh-93103: Deprecate global configuration variables, like
Py_IgnoreEnvironmentFlag
, in the documentation: thePy_InitializeFromConfig()
API should be instead. Patch by Victor Stinner.gh-77782: Deprecate global configuration variable like
Py_IgnoreEnvironmentFlag
: thePy_InitializeFromConfig()
API should be instead. Patch by Victor Stinner.gh-92913: Ensures changes to
PyConfig.module_search_paths
are ignored unlessPyConfig.module_search_paths_set
is setgh-92781: Avoid mixing declarations and code in the C API to fix the compiler warning: "ISO C90 forbids mixed declarations and code" [-Werror=declaration-after-statement]. Patch by Victor Stinner.
gh-92651: Remove the
token.h
header file. There was never any public tokenizer C API. Thetoken.h
header file was only designed to be used by Python internals. Patch by Victor Stinner.gh-92536: Remove legacy Unicode APIs based on
Py_UNICODE*
.gh-85858: Remove the
PyUnicode_InternImmortal()
function and theSSTATE_INTERNED_IMMORTAL
macro. Patch by Victor Stinner.gh-92193: Add new function
PyFunction_SetVectorcall()
to the C API which sets the vectorcall field of a givenPyFunctionObject
.Warning: extensions using this API must preserve the behavior of the unaltered function!
gh-59121: Fixed an assert that prevented
PyRun_InteractiveOne
from providing tracebacks when parsing from the provided FD.bpo-45383: The
PyType_FromSpec()
API will now find and use a metaclass based on the provided bases. An error will be raised if there is a metaclass conflict.
Python 3.11.0 beta 1¶
Release date: 2022-05-06
Security¶
gh-57684: Add the
-P
command line option and thePYTHONSAFEPATH
environment variable to not prepend a potentially unsafe path tosys.path
. Patch by Victor Stinner.
Core and Builtins¶
gh-89519: Chaining classmethod descriptors (introduced in bpo-19072) is deprecated. It can no longer be used to wrap other descriptors such as property(). The core design of this feature was flawed, and it caused a number of downstream problems.
gh-92345:
pymain_run_python()
now importsreadline
andrlcompleter
before sys.path is extended to include the current working directory of an interactive interpreter. Non-interactive interpreters are not affected.bpo-43857: Improve the
AttributeError
message when deleting a missing attribute. Patch by Géry Ogam.gh-92245: Make sure that PEP 523 is respected in all cases. In 3.11a7, specialization may have prevented Python-to-Python calls respecting PEP 523.
gh-92203: Add a closure keyword-only parameter to exec(). It can only be specified when exec-ing a code object that uses free variables. When specified, it must be a tuple, with exactly the number of cell variables referenced by the code object. closure has a default value of None, and it must be None if the code object doesn't refer to any free variables.
gh-91173: Disable frozen modules in debug builds. Patch by Kumar Aditya.
gh-92114: Improve error message when subscript a type with
__class_getitem__
set toNone
.gh-92112: Fix crash triggered by an evil custom
mro()
on a metaclass.gh-92063: The
PRECALL_METHOD_DESCRIPTOR_FAST_WITH_KEYWORDS
instruction now ensures methods are called only on objects of the correct type.gh-92031: Deoptimize statically allocated code objects during
Py_FINALIZE()
so that future_PyCode_Quicken
calls always start with unquickened code.gh-92036: Fix a crash in subinterpreters related to the garbage collector. When a subinterpreter is deleted, untrack all objects tracked by its GC. To prevent a crash in deallocator functions expecting objects to be tracked by the GC, leak a strong reference to these objects on purpose, so they are never deleted and their deallocator functions are not called. Patch by Victor Stinner.
gh-92032: The interpreter can now autocomplete soft keywords, as of now
match
,case
, and_
(wildcard pattern) from PEP 634.gh-87999: The warning emitted by the Python parser for a numeric literal immediately followed by keyword has been changed from deprecation warning to syntax warning.
gh-91869: Fix an issue where specialized opcodes with extended arguments could produce incorrect tracing output or lead to assertion failures.
gh-91603: Speed up
types.UnionType
instantiation. Based on patch provided by Yurii Karabas.gh-89373: If Python is built in debug mode, Python now ensures that deallocator functions leave the current exception unchanged. Patch by Victor Stinner.
gh-91632: Fix a minor memory leak at exit: release the memory of the
generic_alias_iterator
type. Patch by Donghee Na.gh-81548: Octal escapes with value larger than
0o377
now produce aDeprecationWarning
. In a future Python version they will be aSyntaxWarning
and eventually aSyntaxError
.bpo-43950: Use a single compact table for line starts, ends and column offsets. Reduces memory consumption for location info by half
gh-91102: Use Argument Clinic for
EncodingMap
. Patch by Oleg Iarygin.gh-91636: Fixed a crash in a garbage-collection edge-case, in which a
PyFunction_Type.tp_clear
function could leave a python function object in an inconsistent state.gh-91603: Speed up
isinstance()
andissubclass()
checks fortypes.UnionType
. Patch by Yurii Karabas.gh-91625: Fixed a bug in which adaptive opcodes ignored any preceding
EXTENDED_ARG
s on specialization failure.gh-78607: The LLTRACE special build now looks for the name
__lltrace__
defined in module globals, rather than the name__ltrace__
, which had been introduced as a typo.gh-91576: Speed up iteration of ascii strings by 50%. Patch by Kumar Aditya.
gh-89279: Improve interpreter performance on Windows by inlining a few specific macros.
gh-91502: Add a new
_PyFrame_IsEntryFrame()
API function, to check if aPyFrameObject
is an entry frame. Patch by Pablo Galindo.gh-91266: Refactor the
bytearray
strip methodsstrip
,lstrip
andrstrip
to use a common implementation.gh-91479: Replaced the
__note__
field ofBaseException
(added in an earlier version of 3.11) with the final design of PEP 678. Namely,BaseException
gets anadd_note()
method, and its__notes__
field is created when necessary.gh-46055: Speed up right shift of negative integers, by removing unnecessary creation of temporaries. Original patch by Xinhang Xu, reworked by Mark Dickinson.
gh-91462: Make the interpreter's low-level tracing (lltrace) feature output more readable by displaying opcode names (rather than just numbers), and by displaying stack contents before each opcode.
gh-89455: Fixed an uninitialized bool value in the traceback printing code path that was introduced by the initial bpo-45292 exception groups work.
gh-91421: Fix a potential integer overflow in _Py_DecodeUTF8Ex.
gh-91428: Add
static const char *const _PyOpcode_OpName[256] = {...};
toopcode.h
for debug builds to assist in debugging the Python interpreter. It is now more convenient to make various forms of debugging output more human-readable by including opcode names rather than just the corresponding decimal digits.bpo-47120: Make
POP_JUMP_IF_TRUE
,POP_JUMP_IF_FALSE
,POP_JUMP_IF_NONE
andPOP_JUMP_IF_NOT_NONE
virtual, mapping to new relative jump opcodes.bpo-45317: Add internal documentation explaining design of new (for 3.11) frame stack.
bpo-47197: ctypes used to mishandle
void
return types, so that for instance a function declared likectypes.CFUNCTYPE(None, ctypes.c_int)
would be called with signatureint f(int)
instead ofvoid f(int)
. Wasm targets require function pointers to be called with the correct signatures so this led to crashes. The problem is now fixed.bpo-47120: Make opcodes
JUMP_IF_TRUE_OR_POP
andJUMP_IF_FALSE_OR_POP
relative rather than absolute.bpo-47177: Replace the
f_lasti
member of the internal_PyInterpreterFrame
structure with aprev_instr
pointer, which reduces overhead in the main interpreter loop. Thef_lasti
attribute of Python-layer frame objects is preserved for backward-compatibility.bpo-46961: Integer mod/remainder operations, including the three-argument form of
pow()
, now consistently return ints from the global small integer cache when applicable.bpo-46962: Classes and functions that unconditionally declared their docstrings ignoring the
--without-doc-strings
compilation flag no longer do so.The classes affected are
ctypes.UnionType
,pickle.PickleBuffer
,testcapi.RecursingInfinitelyError
, andtypes.GenericAlias
.The functions affected are 24 methods in
ctypes
.Patch by Oleg Iarygin.
bpo-46942: Use Argument Clinic for the
types.MethodType
constructor. Patch by Oleg Iarygin.bpo-46764: Fix wrapping bound methods with @classmethod
bpo-43464: Optimize
set.intersection()
for non-set arguments.bpo-46721: Optimize
set.issuperset()
for non-set argument.bpo-46509: Add type-specialized versions of the
Py_DECREF()
, and use them forfloat
,int
,str
,bool
, andNone
to avoid pointer-chasing at runtime where types are known at C compile time.bpo-46045: Do not use POSIX semaphores on NetBSD
bpo-36819: Fix crashes in built-in encoders with error handlers that return position less or equal than the starting position of non-encodable characters.
bpo-34093:
marshal.dumps()
usesFLAG_REF
for all interned strings. This makes output more deterministic and helps reproducible build.bpo-26579: Added
object.__getstate__
which provides the default implementation of the__getstate__()
method.Copying and pickling instances of subclasses of builtin types bytearray, set, frozenset, collections.OrderedDict, collections.deque, weakref.WeakSet, and datetime.tzinfo now copies and pickles instance attributes implemented as slots.
Library¶
gh-87901: Add the encoding parameter to
os.popen()
.gh-90997: Fix an issue where
dis
utilities may interpret populated inline cache entries as valid instructions.gh-92332: Deprecate
typing.Text
(removal of the class is currently not planned). Patch by Alex Waygood.Deprecate nested classes in enum definitions becoming members -- in 3.13 they will be normal classes; add
member
andnonmember
functions to allow control over results now.gh-92356: Fixed a performance regression in ctypes function calls.
gh-90997: Show the actual named values stored in inline caches when
show_caches=True
is passed todis
utilities.gh-92301: Prefer
close_range()
to iterating over procfs for file descriptor closing insubprocess
for better performance.gh-67248: Sort the miscellaneous topics in Cmd.do_help()
gh-92210: Port
socket.__init__
to Argument Clinic. Patch by Cinder.gh-80010: Add support for generalized ISO 8601 parsing to
datetime.datetime.fromisoformat()
,datetime.date.fromisoformat()
anddatetime.time.fromisoformat()
. Patch by Paul Ganssle.gh-92118: Fix a 3.11 regression in
contextmanager()
, which caused it to propagate exceptions with incorrect tracebacks.gh-90887: Adding
COPYFILE_STAT
,COPYFILE_ACL
andCOPYFILE_XATTR
constants foros.fcopyfile()
available in macOs.gh-91215: For @dataclass, add weakref_slot. Default is False. If True, and if slots=True, add a slot named "__weakref__", which will allow instances to be weakref'd. Contributed by Eric V. Smith
gh-85984: New function os.login_tty() for Unix.
gh-92128: Add
__class_getitem__()
tologging.LoggerAdapter
andlogging.StreamHandler
, allowing them to be parameterized at runtime. Patch by Alex Waygood.gh-92049: Forbid pickling constants
re._constants.SUCCESS
etc. Previously, pickling did not fail, but the result could not be unpickled.gh-92062:
inspect.Parameter
now raisesValueError
ifname
is a keyword, in addition to the existing check that it is an identifier.gh-87390: Add an
__unpacked__
attribute totypes.GenericAlias
. Patch by Jelle Zijlstra.gh-88089: Add support for generic
typing.NamedTuple
.gh-91996: New http.HTTPMethod enum to represent all the available HTTP request methods in a convenient way
gh-91984: Modified test strings in test_argparse.py to not contain trailing spaces before end of line.
gh-91952: Add
encoding="locale"
support toTextIOWrapper.reconfigure()
.gh-91954: Add encoding and errors arguments to
subprocess.getoutput()
andsubprocess.getstatusoutput()
.bpo-47029: Always close the read end of the pipe used by
multiprocessing.Queue
after the last write of buffered data to the write end of the pipe to avoidBrokenPipeError
at garbage collection and atmultiprocessing.Queue.close()
calls. Patch by Géry Ogam.gh-91928: Add
datetime.UTC
alias fordatetime.timezone.utc
.Patch by Kabir Kwatra.
gh-68966: The
mailcap
module is now deprecated and will be removed in Python 3.13. See PEP 594 for the rationale and themimetypes
module for an alternative. Patch by Victor Stinner.gh-91401: Provide a way to disable
subprocess
use ofvfork()
just in case it is ever needed and document the existing mechanism forposix_spawn()
.gh-64783: Fix
signal.NSIG
value on FreeBSD to accept signal numbers greater than 32, likesignal.SIGRTMIN
andsignal.SIGRTMAX
. Patch by Victor Stinner.gh-91910: Add missing f prefix to f-strings in error messages from the
multiprocessing
andasyncio
modules.gh-91860: Add
typing.dataclass_transform()
, implementing PEP 681. Patch by Jelle Zijlstra.gh-91832: Add
required
attribute toargparse.Action
repr output.gh-91827: In the
tkinter
module add methodinfo_patchlevel()
which returns the exact version of the Tcl library as a named tuple similar tosys.version_info
.gh-84461: Add
--enable-wasm-pthreads
to enable pthreads support for WASM builds.Emscripten/node
no longer has threading enabled by default. Include additional file systems.gh-91821: Fix unstable
test_from_tuple
test intest_decimal.py
.gh-91217: Deprecate the xdrlib module.
gh-91217: Deprecate the uu module.
gh-91760: More strict rules will be applied for numerical group references and group names in regular expressions. For now, a deprecation warning is emitted for group references and group names which will be errors in future Python versions.
gh-84461: Add provisional
sys._emscripten_info
named tuple with build-time and run-time information about Emscripten platform.gh-90623:
signal.raise_signal()
andos.kill()
now check immediately for pending signals. Patch by Victor Stinner.gh-91734: Fix OSS audio support on Solaris.
gh-90633: Include the passed value in the exception thrown by
typing.assert_never()
. Patch by Jelle Zijlstra.gh-91700: Compilation of regular expression containing a conditional expression
(?(group)...)
now raises an appropriatere.error
if the group number refers to not defined group. Previously an internal RuntimeError was raised.gh-91231: Add an optional keyword shutdown_timeout parameter to the
multiprocessing.BaseManager
constructor. Kill the process if terminate() takes longer than the timeout. Patch by Victor Stinner.gh-91621: Fix
typing.get_type_hints()
forcollections.abc.Callable
. Patch by Shantanu Jain.gh-90568: Parsing
\N
escapes of Unicode Named Character Sequences in aregular expression
raises nowre.error
instead ofTypeError
.gh-91670: Remove deprecated
SO
config variable insysconfig
.gh-91217: Deprecate the telnetlib module.
gh-91217: Deprecate the sunau module.
gh-91217: Deprecate the spwd module.
gh-91217: Deprecate the sndhdr module, as well as inline needed functionality for
email.mime.MIMEAudio
.gh-91616:
re
module, fixfullmatch()
mismatch when using Atomic Grouping or Possessive Quantifiers.gh-91217: Deprecate the 'pipes' module.
gh-91217: Deprecate the ossaudiodev module.
bpo-47256:
re
module, limit the maximum capturing group to 1,073,741,823 in 64-bit build, this increases the depth of backtracking.gh-91217: Deprecate the nis module.
gh-91595: Fix the comparison of character and integer inside
Tools.gdb.libpython.write_repr()
. Patch by Yu Liu.gh-74166: Add option to raise all errors from
create_connection()
in anExceptionGroup
when it fails to create a connection. The default remains to raise only the last error that had occurred when multiple addresses were tried.gh-91487: Optimize asyncio UDP speed, over 100 times faster when transferring a large file.
gh-91575: Update case-insensitive matching in the
re
module to the latest Unicode version.gh-90622: In
concurrent.futures.process.ProcessPoolExecutor
disallow the "fork" multiprocessing start method when the newmax_tasks_per_child
feature is used as the mix of threads+fork can hang the child processes. Default to using the safe "spawn" start method in that circumstance if nomp_context
was supplied.gh-89022: In
sqlite3
,SQLITE_MISUSE
result codes are now mapped toInterfaceError
instead ofProgrammingError
. Also, more accurate exceptions are raised when binding parameters fail. Patch by Erlend E. Aasland.gh-91526: Stop calling
os.device_encoding(file.fileno())
inTextIOWrapper
. It was complex, never documented, and didn't work for most cases. (Patch by Inada Naoki.)gh-88116: Change the frame-related functions in the
inspect
module to return a regular object (that is backwards compatible with the old tuple-like interface) that include the extended PEP 657 position information (end line number, column and end column). The affected functions are:inspect.getframeinfo()
,inspect.getouterframes()
,inspect.getinnerframes()
,inspect.stack()
andinspect.trace()
. Patch by Pablo Galindo.gh-69093: Add indexing and slicing support to
sqlite3.Blob
. Patch by Aviv Palivoda and Erlend E. Aasland.gh-69093: Add context manager support to
sqlite3.Blob
. Patch by Aviv Palivoda and Erlend E. Aasland.gh-91217: Deprecate nntplib.
gh-91217: Deprecate msilib.
gh-91404: Improve the performance of
re
matching by using computed gotos (or "threaded code") on supported platforms and removing expensive pointer indirections.gh-91217: Deprecate the imghdr module.
gh-91217: Deprecate the crypt module.
bpo-47000: Make
TextIOWrapper
uses locale encoding whenencoding="locale"
is specified even in UTF-8 mode.gh-91230:
warnings.catch_warnings()
now accepts arguments forwarnings.simplefilter()
, providing a more concise way to locally ignore warnings or convert them to errors.gh-91217: Deprecate the chunk module.
Add the
TCP_CONNECTION_INFO
option (available on macOS) tosocket
.bpo-47260: Fix
os.closerange()
potentially being a no-op in a Linux seccomp sandbox.bpo-47087: Implement
typing.Required
andtyping.NotRequired
(PEP 655). Patch by David Foster and Jelle Zijlstra.bpo-47061: Deprecate cgi and cgitb.
bpo-47061: Deprecate audioop.
bpo-47000: Add
locale.getencoding()
to get the current locale encoding. It is similar tolocale.getpreferredencoding(False)
but ignores the Python UTF-8 Mode.bpo-42012: Add
wsgiref.types
, containing WSGI-specific types for static type checking.bpo-47227: Suppress expression chaining for more
re
parsing errors.bpo-47211: Remove undocumented and never working function
re.template()
and flagre.TEMPLATE
. This was later reverted in 3.11.0b2 and deprecated instead.bpo-47135:
decimal.localcontext()
now accepts context attributes via keyword argumentsbpo-43323: Fix errors in the
email
module if the charset itself contains undecodable/unencodable characters.bpo-46841: Disassembly of quickened code.
bpo-46681: Forward gzip.compress() compresslevel to zlib.
bpo-45100: Add
typing.get_overloads()
andtyping.clear_overloads()
. Patch by Jelle Zijlstra.bpo-44807:
typing.Protocol
no longer silently replaces__init__()
methods defined on subclasses. Patch by Adrian Garcia Badaracco.bpo-46787: Fix
concurrent.futures.ProcessPoolExecutor
exception memory leakbpo-46720: Add support for path-like objects to
multiprocessing.set_executable()
for Windows to be on a par with Unix-like systems. Patch by Géry Ogam.bpo-46053: Fix OSS audio support on NetBSD.
bpo-45639:
image/avif
andimage/webp
were added tomimetypes
.bpo-46285: Add command-line option
-p
/--protocol
to modulehttp.server
which specifies the HTTP version to which the server is conformant (HTTP/1.1 conformant servers can now be run from the command-line interface of modulehttp.server
). Patch by Géry Ogam.bpo-44791: Accept ellipsis as the last argument of
typing.Concatenate
.bpo-46547: Remove variables leaking into
pydoc.Helper
class namespace.bpo-46415: Fix ipaddress.ip_{address,interface,network} raising TypeError instead of ValueError if given invalid tuple as address parameter.
bpo-46075:
CookieJar
withDefaultCookiePolicy
now can process cookies from localhost with domain=localhost explicitly specified in Set-Cookie header.bpo-45995: Add a "z" option to the string formatting specification that coerces negative zero floating-point values to positive zero after rounding to the format precision. Contributed by John Belmonte.
bpo-26175: Fully implement the
io.BufferedIOBase
orio.TextIOBase
interface fortempfile.SpooledTemporaryFile
objects. This lets them work correctly with higher-level layers (like compression modules). Patch by Carey Metcalfe.bpo-45138: Fix a regression in the
sqlite3
trace callback where bound parameters were not expanded in the passed statement string. The regression was introduced in Python 3.10 by bpo-40318. Patch by Erlend E. Aasland.bpo-44863: Allow
TypedDict
subclasses to also includeGeneric
as a base class in class based syntax. Thereby allowing the user to define a genericTypedDict
, just like a user-defined generic but withTypedDict
semantics.bpo-44587: Fix BooleanOptionalAction to not automatically add a default string. If a default string is desired, use a formatter to add it.
bpo-43827: All positional-or-keyword parameters to
ABCMeta.__new__
are now positional-only to avoid conflicts with keyword arguments to be passed to__init_subclass__()
.bpo-43218: Prevent creation of a venv whose path contains the PATH separator. This could affect the usage of the activate script. Patch by Dustin Rodrigues.
bpo-38435: Add a
process_group
parameter tosubprocess.Popen
to help move more things off of the unsafepreexec_fn
parameter.bpo-42066: Fix cookies getting sorted in
CookieJar.__iter__()
which is an extra behavior and not mentioned in RFC 2965 or Netscape cookie protocol. Now the cookies inCookieJar
follows the order of theSet-Cookie
header. Patch by Iman Kermani.bpo-40617: Add
create_window_function()
tosqlite3.Connection
for creating aggregate window functions. Patch by Erlend E. Aasland.bpo-40676: Convert
csv
to use Argument Clinic forcsv.field_size_limit()
,csv.get_dialect()
,csv.unregister_dialect()
andcsv.list_dialects()
.bpo-39716: Raise an ArgumentError when the same subparser name is added twice to an
argparse.ArgumentParser
. This is consistent with the (default) behavior when the same option string is added twice to an ArgumentParser.bpo-36073: Raise
ProgrammingError
instead of segfaulting on recursive usage of cursors insqlite3
converters. Patch by Sergey Fedoseev.bpo-34975: Adds a
start_tls()
method toStreamWriter
, which upgrades the connection with TLS using the givenSSLContext
.bpo-22276:
Path
methodsglob()
andrglob()
return only directories if pattern ends with a pathname components separator (/
orsep
). Patch by Eisuke Kawashima.bpo-24905: Add
blobopen()
tosqlite3.Connection
.sqlite3.Blob
allows incremental I/O operations on blobs. Patch by Aviv Palivoda and Erlend E. Aasland.
Documentation¶
gh-91888: Add a new
gh
role to the documentation to link to GitHub issues.gh-91783: Document security issues concerning the use of the function
shutil.unpack_archive()
gh-91547: Remove "Undocumented modules" page.
gh-91298: In
importlib.resources.abc
, refined the documentation of the Traversable Protocol, applying changes from importlib_resources 5.7.1.bpo-44347: Clarify the meaning of dirs_exist_ok, a kwarg of
shutil.copytree()
.bpo-36329: Remove 'make -C Doc serve' in favour of 'make -C Doc htmlview'
bpo-47189: Add a What's New in Python 3.11 entry for the Faster CPython project. Documentation by Ken Jin and Kumar Aditya.
bpo-38668: Update the introduction to documentation for
os.path
to remove warnings that became irrelevant after the implementations of PEP 383 and PEP 529.bpo-47115: The documentation now lists which members of C structs are part of the Limited API/Stable ABI.
bpo-46962: All docstrings in code snippets are now wrapped into
PyDoc_STR
to follow the guideline of PEP 7's Documentation Strings paragraph. Patch by Oleg Iarygin.bpo-26792: Improve the docstrings of
runpy.run_module()
andrunpy.run_path()
. Original patch by Andrew Brezovsky.
Tests¶
gh-92169: Use
warnings_helper.import_deprecated()
to import deprecated modules uniformly in tests. Patch by Hugo van Kemenade.gh-84461: When multiprocessing is enabled, libregrtest can now use a Python executable other than
sys.executable
via the--python
flag.gh-91904: Fix initialization of
PYTHONREGRTEST_UNICODE_GUARD
which prevented running regression tests on non-UTF-8 locale.gh-91752: Added @requires_zlib to test.test_tools.test_freeze.TestFreeze.
gh-91607: Fix
test_concurrent_futures
to test the correct multiprocessing start method context in several cases where the test logic mixed this up.bpo-40280: Threading tests are now skipped on WASM targets without pthread support.
bpo-47109: Test for
ctypes.macholib.dyld
,ctypes.macholib.dylib
, andctypes.macholib.framework
are brought from manual pre-unittest
times toctypes.test
location and structure. Patch by Oleg Iarygin.bpo-29890: Add tests for
ipaddress.IPv4Interface
andipaddress.IPv6Interface
construction with tuple arguments. Original patch and tests by louisom.
Build¶
gh-89452: gdbm-compat is now preferred over ndbm if both are available on the system. This allows avoiding the problematic ndbm.h on macOS.
gh-91731: Python is now built with
-std=c11
compiler option, rather than-std=c99
. Patch by Victor Stinner.bpo-47152: Add script and make target for generating
sre_constants.h
.bpo-47103: Windows
PGInstrument
builds now copy a required DLL into the output directory, making it easier to run the profile stage of a PGO build.
Windows¶
bpo-46907: Update Windows installer to use SQLite 3.38.3.
bpo-47239: Fixed --list and --list-paths output for 适用于Windows的Python启动器 when used in an active virtual environment.
bpo-46907: Update Windows installer to use SQLite 3.38.2.
bpo-46785: Fix race condition between
os.stat()
and unlinking a file on Windows, by using errors codes returned byFindFirstFileW()
when appropriate inwin32_xstat_impl
.bpo-40859: Update Windows build to use xz-5.2.5
macOS¶
bpo-46907: Update macOS installer to SQLite 3.38.4.
Tools/Demos¶
gh-91583: Fix regression in the code generated by Argument Clinic for functions with the
defining_class
parameter.gh-91575: Add script
Tools/scripts/generate_re_casefix.py
and the make targetregen-re
for generating additional data for case-insensitive matching according to the current Unicode version.gh-91551: Remove the ancient Pynche color editor. It has moved to https://gitlab.com/warsaw/pynche
C API¶
gh-88279: Deprecate the C functions:
PySys_SetArgv()
,PySys_SetArgvEx()
,PySys_SetPath()
. Patch by Victor Stinner.gh-92154: Added the
PyCode_GetCode()
function. This function does the equivalent of the Python codegetattr(code_object, 'co_code')
.gh-92173: Fix the
closure
argument toPyEval_EvalCodeEx()
.gh-91320: Fix C++ compiler warnings about "old-style cast" (
g++ -Wold-style-cast
) in the Python C API. Use C++reinterpret_cast<>
andstatic_cast<>
casts when the Python C API is used in C++. Patch by Victor Stinner.gh-80527: Mark functions as deprecated by PEP 623:
PyUnicode_AS_DATA()
,PyUnicode_AS_UNICODE()
,PyUnicode_GET_DATA_SIZE()
,PyUnicode_GET_SIZE()
. Patch by Victor Stinner.gh-91768:
Py_REFCNT()
,Py_TYPE()
,Py_SIZE()
andPy_IS_TYPE()
functions argument type is nowPyObject*
, rather thanconst PyObject*
. Patch by Victor Stinner.gh-91020: Add
PyBytes_Type.tp_alloc
to initializePyBytesObject.ob_shash
for bytes subclasses.bpo-40421: Add
PyFrame_GetLasti
C-API function to access frame object'sf_lasti
attribute safely from C code.bpo-35134: Remove the
Include/code.h
header file. C extensions should only include the main<Python.h>
header file. Patch by Victor Stinner.bpo-47169:
PyOS_CheckStack()
is now exported in the Stable ABI on Windows.bpo-47169:
PyThread_get_thread_native_id()
is excluded from the stable ABI on platforms where it doesn't exist (like Solaris).bpo-46343: Added
PyErr_GetHandledException()
andPyErr_SetHandledException()
as simpler alternatives toPyErr_GetExcInfo()
andPyErr_SetExcInfo()
.They are included in the stable ABI.
Python 3.11.0 alpha 7¶
Release date: 2022-04-05
Core and Builtins¶
bpo-47212: Raise
IndentationError
instead ofSyntaxError
for a bareexcept
with no following indent. ImproveSyntaxError
locations for an un-parenthesized generator used as arguments. Patch by Matthieu Dartiailh.bpo-47186: Replace
JUMP_IF_NOT_EG_MATCH
byCHECK_EG_MATCH
+ jump.bpo-47176: Emscripten builds cannot handle signals in the usual way due to platform limitations. Python can now handle signals. To use, set Module.Py_EmscriptenSignalBuffer to be a single byte SharedArrayBuffer and set Py_EMSCRIPTEN_SIGNAL_HANDLING to 1. Writing a number into the SharedArrayBuffer will cause the corresponding signal to be raised into the Python thread.
bpo-47186: Replace
JUMP_IF_NOT_EXC_MATCH
byCHECK_EXC_MATCH
+ jump.bpo-47120: Replace the absolute jump opcode
JUMP_NO_INTERRUPT
by the relativeJUMP_BACKWARD_NO_INTERRUPT
.bpo-46841: Avoid unnecessary allocations when comparing code objects.
bpo-47182: Fix a crash when using a named unicode character like
"\N{digit nine}"
after the main interpreter has been initialized a second time.bpo-47162: WebAssembly cannot deal with bad function pointer casts (different count or types of arguments). Python can now use call trampolines to mitigate the problem. Define
PY_CALL_TRAMPOLINE
to enable call trampolines.bpo-46775: Some Windows system error codes(>= 10000) are now mapped into the correct errno and may now raise a subclass of
OSError
. Patch by Donghee Na.bpo-47129: Improve error messages in f-string syntax errors concerning empty expressions.
bpo-47117: Fix a crash if we fail to decode characters in interactive mode if the tokenizer buffers are uninitialized. Patch by Pablo Galindo.
bpo-47127: Speed up calls to c functions with keyword arguments by 25% with specialization. Patch by Kumar Aditya.
bpo-47120: Replaced
JUMP_ABSOLUTE
by the relative jumpJUMP_BACKWARD
.bpo-42197:
PyFrame_FastToLocalsWithError()
andPyFrame_LocalsToFast()
are no longer called during profiling nor tracing. C code can access thef_locals
attribute ofPyFrameObject
by callingPyFrame_GetLocals()
.bpo-47070: Improve performance of
array_inplace_repeat
by reducing the number of invocations ofmemcpy
. Refactor therepeat
and inplacerepeat
methods ofarray
,bytes
,bytearray
andunicodeobject
to use the common_PyBytes_Repeat
.bpo-47053: Reduce de-optimization in the specialized
BINARY_OP_INPLACE_ADD_UNICODE
opcode.bpo-47045: Remove the
f_state
field from the _PyInterpreterFrame struct. Add theowner
field to the _PyInterpreterFrame struct to make ownership explicit to simplify clearing and deallocing frames and generators.bpo-46968: Check for the existence of the "sys/auxv.h" header in
faulthandler
to avoid compilation problems in systems where this header doesn't exist. Patch by Pablo Galindobpo-46329: Use low bit of
LOAD_GLOBAL
to indicate whether to push aNULL
before the global. Helps streamline the call sequence a bit.bpo-46841: Quicken bytecode in-place by storing it as part of the corresponding
PyCodeObject
.bpo-47012: Speed up iteration of
bytes
andbytearray
by 30%. Patch by Kumar Aditya.bpo-47009: Improved the performance of
list.append()
and list comprehensions by optimizing for the common case, where no resize is needed. Patch by Dennis Sweeney.bpo-47005: Improve performance of
bytearray_repeat
andbytearray_irepeat
by reducing the number of invocations ofmemcpy
.bpo-46829: Deprecate passing a message into
asyncio.Future.cancel()
andasyncio.Task.cancel()
bpo-46993: Speed up
bytearray
creation fromlist
andtuple
by 40%. Patch by Kumar Aditya.bpo-39829: Removed the
__len__()
call when initializing a list and moved initializing tolist_extend
. Patch by Jeremiah Pascual.bpo-46944: Speed up throwing exception in generator with
METH_FASTCALL
calling convention. Patch by Kumar Aditya.bpo-46841: Modify
STORE_SUBSCR
to use an inline cache entry (rather than its oparg) as an adaptive counter.bpo-46841: Use inline caching for
PRECALL
andCALL
, and remove the internal machinery for managing the (now unused) non-inline caches.bpo-46881: Statically allocate and initialize the latin1 characters.
bpo-46838: Improve syntax errors for incorrect function definitions. Patch by Pablo Galindo
bpo-43721: Fix docstrings of
getter
,setter
, anddeleter
to clarify that they create a new copy of the property.bpo-43224: Make grammar changes required for PEP 646.
Library¶
bpo-47208: Allow vendors to override
CTYPES_MAX_ARGCOUNT
.bpo-23689:
re
module: fix memory leak when a match is terminated by a signal or memory allocation failure. Patch by Ma Lin.bpo-47167: Allow overriding a future compliance check in
asyncio.Task
.bpo-47151: When subprocess tries to use vfork, it now falls back to fork if vfork returns an error. This allows use in situations where vfork isn't allowed by the OS kernel.
bpo-47152: Convert the
re
module into a package. Deprecate modulessre_compile
,sre_constants
andsre_parse
.bpo-4833: Add
ZipFile.mkdir()
bpo-27929: Fix
asyncio.loop.sock_connect()
to only resolve names forsocket.AF_INET
orsocket.AF_INET6
families. Resolution may not make sense for other families, likesocket.AF_BLUETOOTH
andsocket.AF_UNIX
.bpo-14265: Adds the fully qualified test name to unittest output
bpo-47061: Deprecate the aifc module.
bpo-39622: Handle Ctrl+C in asyncio programs to interrupt the main task.
bpo-47101:
hashlib.algorithms_available
now lists only algorithms that are provided by activated crypto providers on OpenSSL 3.0. Legacy algorithms are not listed unless the legacy provider has been loaded into the default OSSL context.bpo-47099: All
URLError
exception messages raised inurllib.request.URLopener
now contain a colon betweenftp error
and the rest of the message. Previously,open_ftp()
missed the colon. Patch by Oleg Iarygin.bpo-47099: Exception chaining is changed from
Exception.with_traceback()
/sys.exc_info()
to PEP 3134. Patch by Oleg Iarygin.bpo-47095:
hashlib
's internal_blake2
module now preferslibb2
from https://www.blake2.net/ over Python's vendored copy of blake2.bpo-47098: The Keccak Code Package for
hashlib
's internal_sha3
module has been replaced with tiny_sha3. The module is used as fallback when Python is built without OpenSSL.bpo-47088: Implement
typing.LiteralString
, part of PEP 675. Patch by Jelle Zijlstra.bpo-42885: Optimize
re.search()
,re.split()
,re.findall()
,re.finditer()
andre.sub()
for regular expressions starting with\A
or^
.bpo-23691: Protect the
re.finditer()
iterator from re-entering.bpo-47067: Optimize calling
GenericAlias
objects by using PEP 590vectorcall
and by replacingPyObject_SetAttrString
withPyObject_SetAttr
.bpo-28080: Add the metadata_encoding parameter in the
zipfile.ZipFile
constructor and the--metadata-encoding
option in thezipfile
CLI to allow reading zipfiles using non-standard codecs to encode the filenames within the archive.bpo-47000: Make
io.text_encoding()
returns "utf-8" when UTF-8 mode is enabled.bpo-42369: Fix thread safety of
zipfile._SharedFile.tell()
to avoid a "zipfile.BadZipFile: Bad CRC-32 for file" exception when reading aZipFile
from multiple threads.bpo-38256: Fix
binascii.crc32()
when it is compiled to use zlib'c crc32 to work properly on inputs 4+GiB in length instead of returning the wrong result. The workaround prior to this was to always feed the function data in increments smaller than 4GiB or to just call the zlib module function.We also have
binascii.crc32()
release the GIL when computing on larger inputs aszlib.crc32()
andhashlib
do.This also boosts performance on Windows as it now uses the zlib crc32 implementation for
binascii.crc32()
for a 2-3x speedup.That the stdlib has a crc32 API in two modules is a known historical oddity. This moves us closer to a single implementation behind them.
bpo-47066: Global inline flags (e.g.
(?i)
) can now only be used at the start of the regular expressions. Using them not at the start of expression was deprecated since Python 3.6.bpo-39394: A warning about inline flags not at the start of the regular expression now contains the position of the flag.
bpo-433030: Add support of atomic grouping (
(?>...)
) and possessive quantifiers (*+
,++
,?+
,{m,n}+
) inregular expressions
.bpo-47062: Implement
asyncio.Runner
context manager.bpo-46382:
dataclass()
slots=True
now correctly omits slots already defined in base classes. Patch by Arie Bovenberg.bpo-47057: Use FASTCALL convention for
FutureIter.throw()
bpo-47061: Deprecate the various modules listed by PEP 594:
aifc, asynchat, asyncore, audioop, cgi, cgitb, chunk, crypt, imghdr, msilib, nntplib, nis, ossaudiodev, pipes, smtpd, sndhdr, spwd, sunau, telnetlib, uu, xdrlib
bpo-34790: Remove passing coroutine objects to