3.14.0a6 - Cpython — ContextQMD

.. date: 2025-02-25-10-25-27 .. gh-issue: 128540 .. nonce: QDz3OL .. release date: 2025-03-14 .. section: macOS

Ensure web browser is launched by :func:webbrowser.open on macOS, even for file:// URLs.

.. date: 2025-03-09-19-57-35 .. gh-issue: 131020 .. nonce: _c87wf .. section: Windows

:source:pylauncher <PC/launcher2.c> correctly detects a BOM when searching for the shebang. Fix by Chris Eibl.

.. date: 2025-02-28-23-24-03 .. gh-issue: 130453 .. nonce: EK0Vk_ .. section: Tools/Demos

Make it possible to override default keywords in :program:pygettext.

.. date: 2025-02-24-21-36-23 .. gh-issue: 85012 .. nonce: 9K1U0E .. section: Tools/Demos

Correctly reset msgctxt when compiling messages in :program:msgfmt.

.. date: 2025-02-22-18-08-35 .. gh-issue: 130453 .. nonce: njRXG8 .. section: Tools/Demos

Extend support for specifying custom keywords in :program:pygettext.

.. date: 2025-02-16-19-00-00 .. gh-issue: 130195 .. nonce: 19274 .. section: Tools/Demos

Add warning messages when pygettext unimplemented -a/--extract-all option is called.

.. date: 2025-02-12-23-24-37 .. gh-issue: 130057 .. nonce: TKUKI6 .. section: Tools/Demos

Add support for translator comments in :program:pygettext.py.

.. date: 2025-02-12-14-58-54 .. gh-issue: 130025 .. nonce: _-mp5K .. section: Tools/Demos

The iOS testbed now correctly handles symlinks used as Python framework references.

.. date: 2025-02-09-20-29-06 .. gh-issue: 129911 .. nonce: uMFtf1 .. section: Tools/Demos

Fix the keyword entry in the help output of :program:pygettext.

.. date: 2025-02-26-15-10-16 .. gh-issue: 129200 .. nonce: XH4TeC .. section: Tests

Multiple iOS testbed runners can now be started at the same time without introducing an ambiguity over simulator ownership.

.. date: 2025-02-20-13-50-07 .. gh-issue: 130292 .. nonce: RvK2Ou .. section: Tests

The iOS testbed will now run successfully on a machine that has not previously run Xcode tests (such as CI configurations).

.. date: 2025-02-20-13-39-12 .. gh-issue: 130293 .. nonce: 5igSsu .. section: Tests

The tests of terminal colorization are no longer sensitive to the value of the TERM variable in the testing environment.

.. date: 2025-02-10-14-34-29 .. gh-issue: 129401 .. nonce: Cq6Ruy .. section: Tests

Fix a flaky test in test_repr_rlock that checks the representation of :class:multiprocessing.RLock.

.. date: 2025-01-26-20-17-58 .. gh-issue: 126332 .. nonce: c0wUS- .. section: Tests

Add unit tests for pyrepl.

.. date: 2024-11-28-20-29-21 .. gh-issue: 127371 .. nonce: PeEhUd .. section: Security

Avoid unbounded buffering for :meth:!tempfile.SpooledTemporaryFile.writelines. Previously, disk spillover was only checked after the lines iterator had been exhausted. This is now done after each line is written.

.. date: 2025-03-14-09-28-13 .. gh-issue: 131204 .. nonce: wogNEX .. section: Library

Use monospace font from System Font Stack for cross-platform support in :class:difflib.HtmlDiff.

.. date: 2025-03-13-19-53-57 .. gh-issue: 131196 .. nonce: 3sBFv2 .. section: Library

Improve performance of :attr:uuid.UUID.hex and :meth:uuid.UUID.__str__ <object.__str__>.

.. date: 2025-03-13-07-06-22 .. gh-issue: 130940 .. nonce: i5cUI5 .. section: Library

The behavior of PyConfig.use_system_logger was modified to be enabled by default on iOS. It remains disabled by default on macOS.

.. date: 2025-03-11-23-58-45 .. gh-issue: 131123 .. nonce: WB6tPh .. section: Library

Supported completions for attributes of convenience variables in :mod:pdb.

.. date: 2025-03-11-20-35-41 .. gh-issue: 93096 .. nonce: Jdt_8a .. section: Library

Removed undocumented CLI python -m difflib. Use python -m doctest Lib/difflib.py -v instead. Patch by Semyon Moroz.

.. date: 2025-03-11-08-07-07 .. gh-issue: 93096 .. nonce: DyPXUX .. section: Library

Removed undocumented -t and -v arguments of python -m pickle. Use python -m doctest Lib/pickle.py -v instead. Patch by Semyon Moroz.

.. date: 2025-03-10-20-23-00 .. gh-issue: 81267 .. nonce: a39381 .. section: Library

Correct :func:time.sleep error message when an object that cannot be interpreted as an integer or float is provided.

.. date: 2025-03-10-14-44-04 .. gh-issue: 93096 .. nonce: kmt59U .. section: Library

Removed undocumented -t and -v arguments of python -m pickletools. Use python -m doctest Lib/pickletools.py -v instead. Patch by Semyon Moroz.

.. date: 2025-03-10-12-26-56 .. gh-issue: 131045 .. nonce: s1TssJ .. section: Library

Fix issue with __contains__, values, and pseudo-members for :class:enum.Flag.

.. date: 2025-03-07-19-24-27 .. gh-issue: 130959 .. nonce: xO8vVS .. section: Library

Fix pure-Python implementation of :func:datetime.time.fromisoformat to reject times with spaces in fractional part (for example, 12:34:56.400 +02:00), matching the C implementation. Patch by Michał Gorny.

.. date: 2025-03-05-20-02-21 .. gh-issue: 130806 .. nonce: o0l2FJ .. section: Library

Deleting :class:gzip.GzipFile before it is closed now emits a :exc:ResourceWarning.

.. date: 2025-03-01-02-19-28 .. gh-issue: 130637 .. nonce: swet54w4rs .. section: Library

Add validation for numeric response data in poplib.POP3.stat() method

.. date: 2025-02-28-11-56-19 .. gh-issue: 130665 .. nonce: cfksVk .. section: Library

Only apply locale to :ref:calendar CLI <calendar-cli> when set via --locale and not via LANG environment variable.

.. date: 2025-02-28-01-10-14 .. gh-issue: 130660 .. nonce: VIThEz .. section: Library

sys.ps1 and sys.ps2 are now restored after :func:code.interact call.

.. date: 2025-02-26-21-21-08 .. gh-issue: 130608 .. nonce: f7ix0Y .. section: Library

Remove dirs_exist_ok argument from :meth:pathlib.Path.copy and :meth:~pathlib.Path.copy_into. These methods are new in Python 3.14.

.. date: 2025-02-25-03-53-00 .. gh-issue: 130461 .. nonce: asr2dg .. section: Library

Remove .. index:: directives from the :mod:uuid module documentation. These directives previously created entries in the general index for :func:~uuid.getnode as well as the :func:~uuid.uuid1, :func:~uuid.uuid3, :func:~uuid.uuid4, :func:~uuid.uuid5, and :func:~uuid.uuid8 constructor functions.

.. date: 2025-02-24-14-46-20 .. gh-issue: 130379 .. nonce: lsef7A .. section: Library

The zipapp module now calculates the list of files to be added to the archive before creating the archive. This avoids accidentally including the target when it is being created in the source directory.

.. date: 2025-02-24-01-49-11 .. gh-issue: 82987 .. nonce: vHfQlG .. section: Library

Inline breakpoints like :func:breakpoint or :func:pdb.set_trace will always stop the program at calling frame, ignoring the skip pattern (if any).

.. date: 2025-02-22-19-44-00 .. gh-issue: 125377 .. nonce: LFTK0H .. section: Library

<tab> at the beginning of the line in :mod:pdb multi-line input will fill in a 4-space indentation now, instead of inserting a \t character.

.. date: 2025-02-21-21-50-21 .. gh-issue: 125413 .. nonce: DEAD0L .. section: Library

Ensure the path returned from :meth:pathlib.Path.copy or :meth:~pathlib.Path.move has fresh :attr:~pathlib.Path.info.

.. date: 2025-02-21-20-22-45 .. gh-issue: 65697 .. nonce: BLxt6y .. section: Library

stdlib configparser will now attempt to validate that keys it writes will not result in file corruption (creating a file unable to be accurately parsed by a future read() call from the same parser). Attempting a corrupting write() will raise an InvalidWriteError.

.. date: 2025-02-21-20-16-32 .. gh-issue: 125413 .. nonce: YJ7Msf .. section: Library

Speed up :meth:Path.copy <pathlib.Path.copy> by making better use of :attr:~pathlib.Path.info internally.

.. date: 2025-02-21-10-32-05 .. gh-issue: 130285 .. nonce: C0fkh7 .. section: Library

Fix corner case for :func:random.sample allowing the counts parameter to specify an empty population. So now, sample([], 0, counts=[]) and sample('abc', k=0, counts=[0, 0, 0]) both give the same result as sample([], 0).

.. date: 2025-02-21-09-05-44 .. gh-issue: 124703 .. nonce: AMJD4Y .. section: Library

Executing quit command in :mod:pdb will raise :exc:bdb.BdbQuit when :mod:pdb is started from an interactive console using :func:breakpoint or :func:pdb.set_trace.

.. date: 2025-02-19-20-29-33 .. gh-issue: 107773 .. nonce: 7y6Ug2 .. section: Library

Make :mod:datetime subclass :meth:~object.__repr__ consistent both implementations. Patch by Semyon Moroz.

.. date: 2025-02-19-19-29-19 .. gh-issue: 130250 .. nonce: T00tql .. section: Library

Fix regression in traceback.print_last().

.. date: 2025-02-19-08-06-37 .. gh-issue: 123471 .. nonce: br7uyR .. section: Library

Make concurrent iterations over :class:itertools.batched safe under free-threading.

.. date: 2025-02-19-01-29-16 .. gh-issue: 57537 .. nonce: 4tdVuK .. section: Library

Support breakpoints for :mod:zipimport modules on :mod:pdb

.. date: 2025-02-17-21-16-51 .. gh-issue: 130230 .. nonce: 9ta9P9 .. section: Library

Fix crash in :func:pow with only :class:~decimal.Decimal third argument.

.. date: 2025-02-17-21-01-25 .. gh-issue: 126944 .. nonce: 49YTHZ .. section: Library

Show explicit errors when required arguments of :mod:pdb commands are missing

.. date: 2025-02-17-12-36-39 .. gh-issue: 127750 .. nonce: ZC-hBq .. section: Library

Improve repr of :class:functools.singledispatchmethod methods and descriptors.

.. date: 2025-02-16-18-13-40 .. gh-issue: 128520 .. nonce: iZtOMz .. section: Library

Apply type conversion consistently in :class:pathlib.PurePath and :class:~pathlib.Path methods can accept a path object as an argument, such as :meth:~pathlib.PurePath.match and :meth:~pathlib.Path.rename. The argument is now converted to path object if it lacks a :meth:~pathlib.PurePath.with_segments attribute, and not otherwise.

.. date: 2025-02-16-10-12-27 .. gh-issue: 118761 .. nonce: TNw5ZC .. section: Library

Reverts a change in the previous release attempting to make some stdlib imports used within the :mod:subprocess module lazy as this was causing errors during __del__ finalizers calling methods such as terminate, or kill, or send_signal.

.. date: 2025-02-16-08-56-48 .. gh-issue: 130164 .. nonce: vvoaU2 .. section: Library

Fixed failure to raise :exc:TypeError in :meth:inspect.Signature.bind for positional-only arguments provided by keyword when a variadic keyword argument (e.g. **kwargs) is present.

.. date: 2025-02-15-12-36-49 .. gh-issue: 130151 .. nonce: 3IFumF .. section: Library

Fix reference leaks in :func:!_hashlib.hmac_new and :func:!_hashlib.hmac_digest. Patch by Bénédikt Tran.

.. date: 2025-02-15-07-50-37 .. gh-issue: 130145 .. nonce: I0CkV0 .. section: Library

Fix :meth:!asyncio.AbstractEventloop.run_forever when another loop is already running.

.. date: 2025-02-15-01-37-47 .. gh-issue: 130139 .. nonce: gntc7B .. section: Library

Fix bug where :func:ast.parse did not error on AST input which is not of the correct type, when called with optimize=False.

.. date: 2025-02-14-23-38-03 .. gh-issue: 127260 .. nonce: dXQ8P0 .. section: Library

Forbid the use of colon (":") as a fractional component separator and other improvements to the consistency of error raising between the C and Python implementations of :meth:datetime.time.fromisoformat and :meth:datetime.datetime.fromisoformat. Patch by Semyon Moroz.

.. date: 2025-02-13-15-10-56 .. gh-issue: 85795 .. nonce: jeXXI9 .. section: Library

Using :func:super and __class__ :term:closure variable in user-defined methods of :class:typing.NamedTuple subclasses is now explicitly prohibited at runtime. Contributed by Bartosz Sławecki in :gh:130082.

.. date: 2025-02-13-02-03-38 .. gh-issue: 118761 .. nonce: le_qEg .. section: Library

Improve import time of :mod:cmd by lazy importing :mod:inspect and removing :mod:string. Patch by Semyon Moroz.

.. date: 2025-02-12-12-38-24 .. gh-issue: 129726 .. nonce: jB0sxu .. section: Library

Fix :class:gzip.GzipFile raising an unraisable exception during garbage collection when referring to a temporary object by breaking the reference loop with :mod:weakref.

.. date: 2025-02-11-18-37-26 .. gh-issue: 127750 .. nonce: 41SDhF .. section: Library

Remove broken :func:functools.singledispatchmethod caching introduced in :gh:85160. Achieve the same performance using different optimization.

.. date: 2025-02-11-06-42-17 .. gh-issue: 129948 .. nonce: ZcugY9 .. section: Library

Add support for shared :class:set to :class:multiprocessing.managers.SyncManager via :meth:SyncManager.set() <multiprocessing.managers.SyncManager.set>.

.. date: 2025-02-10-19-16-48 .. gh-issue: 129965 .. nonce: B6wik0 .. section: Library

Update MIME types for .avi and .wav. Add MIME types for .docx, .pptx, .xlsx, .epub, .flac, .m4a, .odg, .odp, .ods, .odt, .oga, .ogg, .ogx and .weba. Patch by Hugo van Kemenade.

.. date: 2025-02-10-09-45-49 .. gh-issue: 129889 .. nonce: PBHXU5 .. section: Library

Support context manager protocol by :class:contextvars.Token. Patch by Andrew Svetlov.

.. date: 2025-02-08-15-13-43 .. gh-issue: 97850 .. nonce: jQ0CvW .. section: Library

Update the deprecation warning of importlib.abc.Loader.load_module.

.. date: 2025-02-05-15-17-31 .. gh-issue: 129678 .. nonce: GIUrmV .. section: Library

:class:configparser.ConfigParser: do not write an empty unnamed section

.. date: 2025-02-02-23-47-35 .. gh-issue: 128641 .. nonce: GFs673 .. section: Library

Restore :meth:configparser.ConfigParser.read performance.

.. date: 2025-02-02-16-30-27 .. gh-issue: 129569 .. nonce: i0kPOG .. section: Library

Fix :func:unicodedata.normalize to always return a built-in :class:str object when given an input of a :class:str subclass, regardless of whether the string is already normalized.

.. date: 2025-01-30-22-49-42 .. gh-issue: 128231 .. nonce: SuEC18 .. section: Library

Execution of multiple statements in the new REPL now stops immediately upon the first exception encountered. Patch by Bartosz Sławecki.

.. date: 2025-01-26-19-35-06 .. gh-issue: 96092 .. nonce: mMg3gL .. section: Library

Fix bug in :func:traceback.walk_stack called with None where it was skipping more frames than in prior versions. This bug fix also changes walk_stack to walk the stack in the frame where it was called rather than where it first gets used.

.. date: 2025-01-26-15-35-53 .. gh-issue: 129288 .. nonce: wB3uxU .. section: Library

Add optional l2_cid and l2_bdaddr_type fields to :mod:socket BTPROTO_L2CAP sockaddr tuple.

.. date: 2025-01-15-12-04-30 .. gh-issue: 128703 .. nonce: 6WPf38 .. section: Library

Fix :func:mimetypes.guess_type to use default mapping for empty Content-Type in registry.

.. date: 2025-01-08-15-14-17 .. gh-issue: 128647 .. nonce: GabglU .. section: Library

Eagerly write to buffers passed to :class:gzip.GzipFile's :meth:~io.BufferedIOBase.readinto and :meth:~io.BufferedIOBase.readinto1 implementations, avoiding unnecessary allocations. Patch by Chris Markiewicz.

.. date: 2024-12-23-17-00-35 .. gh-issue: 128184 .. nonce: cRQvgM .. section: Library

Improve display of :class:annotationlib.ForwardRef object within :class:inspect.Signature representations. This also fixes a :exc:NameError that was raised when using :func:dataclasses.dataclass on classes with unresolvable forward references.

.. date: 2024-12-17-18-53-21 .. gh-issue: 128041 .. nonce: W96kAr .. section: Library

Add :meth:concurrent.futures.ProcessPoolExecutor.terminate_workers and :meth:concurrent.futures.ProcessPoolExecutor.kill_workers as ways to terminate or kill all living worker processes in the given pool. (Contributed by Charles Machalow in :gh:130849.)

.. date: 2024-12-05-19-54-16 .. gh-issue: 127647 .. nonce: Xd78Vs .. section: Library

Add protocols :class:io.Reader and :class:io.Writer as alternatives to :class:typing.IO, :class:typing.TextIO, and :class:typing.BinaryIO.

.. date: 2024-11-27-23-29-05 .. gh-issue: 109798 .. nonce: OPj1CT .. section: Library

Added additional information into error messages in :mod:datetime, and made the messages more consistent between the C and Python implementations. Patch by Semyon Moroz.

.. date: 2024-10-20-13-01-05 .. gh-issue: 125746 .. nonce: wDLTay .. section: Library

Delay deprecated :meth:!zipimport.zipimporter.load_module removal time to 3.15. Use :meth:zipimport.zipimporter.exec_module instead.

.. date: 2024-10-18-10-27-54 .. gh-issue: 74028 .. nonce: 4d4vVD .. section: Library

Add the optional buffersize parameter to :meth:concurrent.futures.Executor.map to limit the number of submitted tasks whose results have not yet been yielded. If the buffer is full, iteration over the iterables pauses until a result is yielded from the buffer.

.. date: 2024-10-05-13-25-07 .. gh-issue: 124927 .. nonce: uzNA32 .. section: Library

Non-printing characters are now properly handled in the new REPL.

.. date: 2024-09-16-17-03-52 .. gh-issue: 124096 .. nonce: znin0O .. section: Library

Turn on virtual terminal mode and enable bracketed paste in REPL on Windows console. (If the terminal does not support bracketed paste, enabling it does nothing.)

.. date: 2024-06-28-11-27-25 .. gh-issue: 89083 .. nonce: DKL_Sk .. section: Library

Add :func:uuid.uuid7 for generating UUIDv7 objects as specified in :rfc:9562. Patch by Bénédikt Tran.

.. date: 2024-06-17-17-31-27 .. gh-issue: 89083 .. nonce: nW00Yq .. section: Library

Add :func:uuid.uuid6 for generating UUIDv6 objects as specified in :rfc:9562. Patch by Bénédikt Tran.

.. date: 2024-04-30-14-03-09 .. gh-issue: 117151 .. nonce: yt2H8c .. section: Library

Increase io.DEFAULT_BUFFER_SIZE from 8k to 128k and adjust :func:open on platforms where :meth:os.fstat provides a st_blksize field (such as Linux) to use max(min(blocksize, 8 MiB), io.DEFAULT_BUFFER_SIZE) rather than always using the device block size. This should improve I/O performance. Patch by Romain Morotti.

.. date: 2023-06-08-07-56-05 .. gh-issue: 105499 .. nonce: 7jV6cP .. section: Library

Make :class:types.UnionType an alias for :class:typing.Union. Both int | str and Union[int, str] now create instances of the same type. Patch by Jelle Zijlstra.

.. date: 2022-05-28-19-41-02 .. gh-issue: 93096 .. nonce: qjUyRG .. section: Library

Document the command-line for :mod:mimetypes. It now exits with 1 on failure instead of 0 and 2 on incorrect command-line parameters instead of 1. Also, errors are printed to stderr instead of stdout and their text is made tighter. Patch by Oleg Iarygin and Hugo van Kemenade.

.. date: 2025-02-22-02-24-39 .. gh-issue: 125722 .. nonce: zDIUFV .. section: Documentation

Require Sphinx 8.2.0 or later to build the Python documentation. Patch by Adam Turner.

.. date: 2025-02-21-08-44-31 .. gh-issue: 129712 .. nonce: 4AcfWQ .. section: Documentation

The wheel tags supported by each macOS universal SDK option are now documented.

.. date: 2025-02-16-14-57-00 .. gh-issue: 46236 .. nonce: 2HuS4S .. section: Documentation

C API: Document :c:func:PyUnicode_RSplit, :c:func:PyUnicode_Partition and :c:func:PyUnicode_RPartition.

.. date: 2025-03-12-11-19-46 .. gh-issue: 131141 .. nonce: tQz594 .. section: Core and Builtins

Fix data race in :data:sys.monitoring instrumentation while registering callback.

.. date: 2025-03-10-21-46-37 .. gh-issue: 130804 .. nonce: 0PpcTx .. section: Core and Builtins

Fix support of unicode characters on Windows in the new REPL.

.. date: 2025-03-06-22-56-02 .. gh-issue: 130932 .. nonce: QVHaKT .. section: Core and Builtins

Fix incorrect exception handling in _PyModule_IsPossiblyShadowing

.. date: 2025-03-05-21-52-20 .. gh-issue: 122029 .. nonce: d_z93q .. section: Core and Builtins

:func:sys.setprofile and :func:sys.settrace will not generate a c_call event for INSTRUMENTED_CALL_FUNCTION_EX if the callable is a method with a C function wrapped, because we do not generate c_return event in such case.

.. date: 2025-03-05-15-19-21 .. gh-issue: 129964 .. nonce: jqu89w .. section: Core and Builtins

Fix JIT crash on Windows on Arm. Patch by Diego Russo and Brandt Bucher.

.. date: 2025-03-04-20-33-28 .. gh-issue: 130851 .. nonce: MT9j7n .. section: Core and Builtins

Fix a crash in the :term:free threading build when constructing a :class:code object with :attr:~codeobject.co_consts that contains instances of types that are not otherwise generated by the bytecode compiler.

.. date: 2025-03-04-15-12-32 .. gh-issue: 128534 .. nonce: 3A0K3D .. section: Core and Builtins

Ensure that both left and right branches have the same source for async for loops. Add these branches to the co_branches() iterator.

.. date: 2025-03-03-20-33-44 .. gh-issue: 130794 .. nonce: LwtGQc .. section: Core and Builtins

Fix memory leak in the :term:free threaded <free threading> build when resizing a shared list or dictionary from multiple short-lived threads.

.. date: 2025-03-03-01-21-04 .. gh-issue: 130415 .. nonce: ibOV6B .. section: Core and Builtins

Improve JIT understanding of integers in boolean context.

.. date: 2025-02-28-16-13-02 .. gh-issue: 130382 .. nonce: 66VTmy .. section: Core and Builtins

Fix PyRefTracer_DESTROY not being sent from :file:Python/ceval.c Py_DECREF().

.. date: 2025-02-28-13-34-51 .. gh-issue: 130574 .. nonce: ujr3Vx .. section: Core and Builtins

Renumber :opcode:RESUME from 149 to 128.

.. date: 2025-02-27-18-48-42 .. gh-issue: 124878 .. nonce: DS0MIL .. section: Core and Builtins

Fix race conditions during runtime finalization that could lead to accessing freed memory.

.. date: 2025-02-27-17-05-05 .. gh-issue: 130415 .. nonce: iijvfW .. section: Core and Builtins

Improve the experimental JIT's ability to narrow boolean values based on the results of truthiness tests.

.. date: 2025-02-27-15-07-06 .. gh-issue: 130618 .. nonce: JTcsRB .. section: Core and Builtins

Fix a bug that was causing UnicodeDecodeError or SystemError to be raised when using f-strings with lambda expressions with non-ASCII characters. Patch by Pablo Galindo

.. date: 2025-02-27-10-47-09 .. gh-issue: 123044 .. nonce: 8182Un .. section: Core and Builtins

Make sure that the location of branch targets in match cases is in the body, not the pattern.

.. date: 2025-02-26-10-32-48 .. gh-issue: 128534 .. nonce: JEiQex .. section: Core and Builtins

Add branch monitoring (BRANCH_LEFT and BRANCH_RIGHT events) for async for loops.

.. date: 2025-02-24-14-25-36 .. gh-issue: 130163 .. nonce: rGpc9v .. section: Core and Builtins

Fix possible crashes related to concurrent change and use of the :mod:sys module attributes.

.. date: 2025-02-23-20-48-31 .. gh-issue: 122029 .. nonce: iW8GvA .. section: Core and Builtins

INSTRUMENTED_CALL_KW will expand the method before monitoring to reflect the actual behavior more accurately.

.. date: 2025-02-22-22-49-00 .. gh-issue: 130415 .. nonce: WyxBYS .. section: Core and Builtins

Improve JIT's ability to optimize strings in boolean contexts.

.. date: 2025-02-21-11-12-41 .. gh-issue: 130396 .. nonce: SIenSP .. section: Core and Builtins

Use actual stack limits (from :manpage:pthread_getattr_np(3)) for linux, and other systems with _GNU_SOURCE defined, when determining limits for C stack protection.

.. date: 2025-02-17-18-59-33 .. gh-issue: 128396 .. nonce: iVtoYY .. section: Core and Builtins

Fix a crash that occurs when calling :func:locals inside an inline comprehension that uses the same local variable as the outer frame scope where the variable is a free or cell var.

.. date: 2025-02-17-15-32-26 .. gh-issue: 129107 .. nonce: fPPBLw .. section: Core and Builtins

Fix two more :class:bytearray functions for :term:free threading.

.. date: 2025-02-17-12-48-00 .. gh-issue: 127705 .. nonce: Qad2hx .. section: Core and Builtins

Use tagged references (_PyStackRef) for the default build as well as for the free-threading build. This has a small negative performance impact short-term but will enable larger speedups in the future and significantly reduce maintenance costs by allowing a single implementation of tagged references in the future.

.. date: 2025-02-14-00-32-52 .. gh-issue: 130094 .. nonce: m3EF9E .. section: Core and Builtins

Fix two race conditions involving concurrent imports that could lead to spurious failures with :exc:ModuleNotFoundError.

.. date: 2025-02-13-20-42-53 .. gh-issue: 129107 .. nonce: _olg-L .. section: Core and Builtins

Make :class:bytearray iterator safe under :term:free threading.

.. date: 2025-02-13-12-31-53 .. gh-issue: 115802 .. nonce: 0kN4xM .. section: Core and Builtins

Use the more efficient "medium" code model for JIT-compiled code on supported platforms.

.. date: 2025-02-13-02-39-42 .. gh-issue: 107956 .. nonce: dLguDW .. section: Core and Builtins

A build-details.json file is now install in the platform-independent standard library directory (:pep:739 implementation).

.. date: 2025-02-13-00-28-43 .. gh-issue: 116042 .. nonce: 861juq .. section: Core and Builtins

Fix location for SyntaxErrors of invalid escapes in the tokenizer. Patch by Pablo Galindo

.. date: 2025-02-12-12-44-36 .. gh-issue: 91079 .. nonce: 8Nq08d .. section: Core and Builtins

Change C stack overflow protection to consider the amount of stack consumed, rather than a counter. This allows deeper recursion in many cases, but remains safe.

.. date: 2025-02-11-22-20-21 .. gh-issue: 129715 .. nonce: mopO8n .. section: Core and Builtins

Improve the experimental JIT's handling of returns to unknown callers.

.. date: 2025-02-11-20-38-37 .. gh-issue: 129983 .. nonce: _1Fujo .. section: Library

Fix data race in compile_template in :file:sre.c.

.. date: 2025-02-10-20-01-56 .. gh-issue: 129967 .. nonce: J60tEl .. section: Core and Builtins

Fix a race condition in the :term:free threading build when repr(set) is called concurrently with set.clear().

.. date: 2025-02-10-11-30-13 .. gh-issue: 129953 .. nonce: wipsl_ .. section: Core and Builtins

The internal (evaluation) stack is now spilled to memory whenever execution escapes from the interpreter or JIT compiled code. This should have no observable effect in either Python or builtin extensions, but will allow various important optimizations in the future.

.. date: 2025-02-09-11-30-38 .. gh-issue: 129515 .. nonce: 3L3vmo .. section: Core and Builtins

Clarify syntax error messages for conditional expressions when a statement is specified before an :keyword:if or after an :keyword:else keyword.

.. date: 2025-02-08-09-55-33 .. gh-issue: 129349 .. nonce: PkcG-l .. section: Core and Builtins

:meth:bytes.fromhex and :meth:bytearray.fromhex now accepts ASCII :class:bytes and :term:bytes-like objects <bytes-like object>.

.. date: 2025-01-25-20-07-03 .. gh-issue: 129149 .. nonce: njeFJi .. section: Core and Builtins

Add fast path for medium-size integers in :c:func:PyLong_FromSsize_t. Patch by Chris Eibl.

.. date: 2025-01-20-23-34-14 .. gh-issue: 129107 .. nonce: T5gBva .. section: Core and Builtins

Make the :type:bytearray safe under :term:free threading.

.. date: 2025-01-18-10-50-04 .. gh-issue: 128974 .. nonce: KltI-A .. section: Core and Builtins

Fix a crash in :meth:UnicodeError.__str__ <object.__str__> when custom attributes implement :meth:~object.__str__ with side-effects. Patch by Bénédikt Tran.

.. date: 2024-12-15-16-56-26 .. gh-issue: 126085 .. nonce: BvyEXk .. section: Core and Builtins

:class:typing.TypeAliasType now supports star unpacking.

.. date: 2024-10-29-23-30-35 .. gh-issue: 125331 .. nonce: quKQ7V .. section: Core and Builtins

from __future__ import barry_as_FLUFL now works in more contexts, including when it is used in files, with the -c flag, and in the REPL when there are multiple statements on the same line. Previously, it worked only on subsequent lines in the REPL, and when the appropriate flags were passed directly to :func:compile. Patch by Pablo Galindo.

.. date: 2024-10-19-20-22-19 .. gh-issue: 121464 .. nonce: IHwfpK .. section: Core and Builtins

Make concurrent iterations over the same :func:enumerate iterator safe under free-threading. See Strategy for Iterators in Free Threading <https://github.com/python/cpython/issues/124397>_.

.. date: 2024-10-11-10-41-05 .. gh-issue: 87790 .. nonce: mlfEGl .. section: Core and Builtins

Support underscore and comma as thousands separators in the fractional part for floating-point presentation types of the new-style string formatting (with :func:format or :ref:f-strings). Patch by Sergey B Kirpichev.

.. date: 2024-09-25-13-45-01 .. gh-issue: 124445 .. nonce: zfsD7q .. section: Core and Builtins

Fix specialization of generic aliases that are generic over a :class:typing.ParamSpec and have been specialized with a nested type variable.

.. date: 2024-06-24-20-08-55 .. gh-issue: 120608 .. nonce: d75n8U .. section: Core and Builtins

Adapt :func:reversed for use in the free-threading build. The :func:reversed is still not thread-safe in the sense that concurrent iterations may see the same object, but they will not corrupt the interpreter state.

.. date: 2022-12-21-14-28-01 .. gh-issue: 100388 .. nonce: vne8ky .. section: Library

Fix the platform._sys_version() method when __DATE__ is undefined at buildtime by changing default buildtime datetime string to the UNIX epoch.

.. bpo: 44369 .. date: 2021-06-09-23-04-58 .. nonce: R7QkFv .. section: Core and Builtins

Improve syntax errors for incorrectly closed strings. Patch by Pablo Galindo

.. date: 2025-03-12-08-29-23 .. gh-issue: 111178 .. nonce: Jny_YJ .. section: C API

Fix :c:type:PyCMethod API: replace size_t nargs with Py_ssize_t nargs in :c:type:PyCMethod. Patch by Victor Stinner.

.. date: 2025-03-07-14-49-06 .. gh-issue: 130947 .. nonce: _Pw0IX .. section: C API

Add again :c:func:PySequence_Fast to the limited C API. Patch by Victor Stinner.

.. date: 2025-02-19-14-41-26 .. gh-issue: 128863 .. nonce: TELwyV .. section: C API

The following private functions are deprecated and planned for removal in Python 3.18:

:c:func:!_PyUnicodeWriter_Init: replace _PyUnicodeWriter_Init(&writer) with :c:func:writer = PyUnicodeWriter_Create(0) <PyUnicodeWriter_Create>.
:c:func:!_PyUnicodeWriter_Finish: replace _PyUnicodeWriter_Finish(&writer) with :c:func:PyUnicodeWriter_Finish(writer) <PyUnicodeWriter_Finish>.
:c:func:!_PyUnicodeWriter_Dealloc: replace _PyUnicodeWriter_Dealloc(&writer) with :c:func:PyUnicodeWriter_Discard(writer) <PyUnicodeWriter_Discard>.
:c:func:!_PyUnicodeWriter_WriteChar: replace _PyUnicodeWriter_WriteChar(&writer, ch) with :c:func:PyUnicodeWriter_WriteChar(writer, ch) <PyUnicodeWriter_WriteChar>.
:c:func:!_PyUnicodeWriter_WriteStr: replace _PyUnicodeWriter_WriteStr(&writer, str) with :c:func:PyUnicodeWriter_WriteStr(writer, str) <PyUnicodeWriter_WriteStr>.
:c:func:!_PyUnicodeWriter_WriteSubstring: replace _PyUnicodeWriter_WriteSubstring(&writer, str, start, end) with :c:func:PyUnicodeWriter_WriteSubstring(writer, str, start, end) <PyUnicodeWriter_WriteSubstring>.
:c:func:!_PyUnicodeWriter_WriteASCIIString: replace _PyUnicodeWriter_WriteASCIIString(&writer, str) with :c:func:PyUnicodeWriter_WriteUTF8(writer, str) <PyUnicodeWriter_WriteUTF8>.
:c:func:!_PyUnicodeWriter_WriteLatin1String: replace _PyUnicodeWriter_WriteLatin1String(&writer, str) with :c:func:PyUnicodeWriter_WriteUTF8(writer, str) <PyUnicodeWriter_WriteUTF8>.
:c:func:!_PyUnicodeWriter_Prepare: (no replacement).
:c:func:!_PyUnicodeWriter_PrepareKind: (no replacement).

The pythoncapi-compat project <https://github.com/python/pythoncapi-compat/>__ can be used to get these new public functions on Python 3.13 and older.

Patch by Victor Stinner.

.. date: 2025-02-13-00-57-05 .. gh-issue: 45325 .. nonce: Cwif9z .. section: C API

Add a new p format parameter to :c:func:Py_BuildValue that allows to take a C integer and produce a Python :class:bool object. Patch by Pablo Galindo.

.. date: 2025-03-10-10-52-25 .. gh-issue: 131035 .. nonce: KF1w4j .. section: Build

Use -flto=thin for faster build times using clang-cl on Windows. Patch by Chris Eibl.

.. date: 2025-03-01-18-27-42 .. gh-issue: 130740 .. nonce: nDFSHR .. section: Build

Ensure that Python.h is included before stdbool.h unless pyconfig.h is included before or in some platform-specific contexts.

.. date: 2025-02-13-19-21-41 .. gh-issue: 130090 .. nonce: 3ngJaV .. section: Build

Building with PlatformToolset=ClangCL on Windows now supports PGO (profile guided optimization). Patch by Chris Eibl with invaluable support from Steve Dover.

.. date: 2025-02-11-08-06-44 .. gh-issue: 129819 .. nonce: 7rn4dY .. section: Build

Allow building the JIT with the tailcall interpreter.

.. date: 2025-02-11-07-55-28 .. gh-issue: 129989 .. nonce: kaSKlD .. section: Build

Fix a bug where the tailcall interpreter was enabled when --without-tail-call-interp was provided to the configure script.

.. date: 2025-02-07-21-20-21 .. gh-issue: 129838 .. nonce: fkuiEc .. section: Build

Don't redefine _Py_NO_SANITIZE_UNDEFINED when compiling with a recent GCC version and undefined sanitizer enabled.

.. date: 2023-04-02-14-20-29 .. gh-issue: 82909 .. nonce: LGcZJy .. section: Build

#pragma-based linking with python3*.lib can now be switched off with :c:expr:Py_NO_LINK_LIB. Patch by Jean-Christophe Fillion-Robin.