cpython/Doc/whatsnew/3.11.rst

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****************************
What's New In Python 3.11
****************************
:Release: |release|
:Date: |today|
.. Rules for maintenance:
* Anyone can add text to this document. Do not spend very much time
on the wording of your changes, because your text will probably
get rewritten to some degree.
* The maintainer will go through Misc/NEWS periodically and add
changes; it's therefore more important to add your changes to
Misc/NEWS than to this file.
* This is not a complete list of every single change; completeness
is the purpose of Misc/NEWS. Some changes I consider too small
or esoteric to include. If such a change is added to the text,
I'll just remove it. (This is another reason you shouldn't spend
too much time on writing your addition.)
* If you want to draw your new text to the attention of the
maintainer, add 'XXX' to the beginning of the paragraph or
section.
* It's OK to just add a fragmentary note about a change. For
example: "XXX Describe the transmogrify() function added to the
socket module." The maintainer will research the change and
write the necessary text.
* You can comment out your additions if you like, but it's not
necessary (especially when a final release is some months away).
* Credit the author of a patch or bugfix. Just the name is
sufficient; the e-mail address isn't necessary.
* It's helpful to add the bug/patch number as a comment:
XXX Describe the transmogrify() function added to the socket
module.
(Contributed by P.Y. Developer in :issue:`12345`.)
This saves the maintainer the effort of going through the Mercurial log
when researching a change.
This article explains the new features in Python 3.11, compared to 3.10.
For full details, see the :ref:`changelog <changelog>`.
.. note::
Prerelease users should be aware that this document is currently in draft
form. It will be updated substantially as Python 3.11 moves towards release,
so it's worth checking back even after reading earlier versions.
Summary -- Release highlights
=============================
.. This section singles out the most important changes in Python 3.11.
Brevity is key.
.. PEP-sized items next.
New Features
============
.. _whatsnew311-pep657:
Enhanced error locations in tracebacks
--------------------------------------
When printing tracebacks, the interpreter will now point to the exact expression
that caused the error instead of just the line. For example:
.. code-block:: python
Traceback (most recent call last):
File "distance.py", line 11, in <module>
print(manhattan_distance(p1, p2))
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "distance.py", line 6, in manhattan_distance
return abs(point_1.x - point_2.x) + abs(point_1.y - point_2.y)
^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'x'
Previous versions of the interpreter would point to just the line making it
ambiguous which object was ``None``. These enhanced errors can also be helpful
when dealing with deeply nested dictionary objects and multiple function calls,
.. code-block:: python
Traceback (most recent call last):
File "query.py", line 37, in <module>
magic_arithmetic('foo')
^^^^^^^^^^^^^^^^^^^^^^^
File "query.py", line 18, in magic_arithmetic
return add_counts(x) / 25
^^^^^^^^^^^^^
File "query.py", line 24, in add_counts
return 25 + query_user(user1) + query_user(user2)
^^^^^^^^^^^^^^^^^
File "query.py", line 32, in query_user
return 1 + query_count(db, response['a']['b']['c']['user'], retry=True)
~~~~~~~~~~~~~~~~~~^^^^^
TypeError: 'NoneType' object is not subscriptable
as well as complex arithmetic expressions:
.. code-block:: python
Traceback (most recent call last):
File "calculation.py", line 54, in <module>
result = (x / y / z) * (a / b / c)
~~~~~~^~~
ZeroDivisionError: division by zero
See :pep:`657` for more details. (Contributed by Pablo Galindo, Batuhan Taskaya
and Ammar Askar in :issue:`43950`.)
.. note::
This feature requires storing column positions in code objects which may
result in a small increase of disk usage of compiled Python files or
interpreter memory usage. To avoid storing the extra information and/or
deactivate printing the extra traceback information, the
:option:`-X` ``no_debug_ranges`` command line flag or the :envvar:`PYTHONNODEBUGRANGES`
environment variable can be used.
Column information for code objects
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The information used by the enhanced traceback feature is made available as a
general API that can be used to correlate bytecode instructions with source
code. This information can be retrieved using:
- The :meth:`codeobject.co_positions` method in Python.
- The :c:func:`PyCode_Addr2Location` function in the C-API.
The :option:`-X` ``no_debug_ranges`` option and the environment variable
:envvar:`PYTHONNODEBUGRANGES` can be used to disable this feature.
See :pep:`657` for more details. (Contributed by Pablo Galindo, Batuhan Taskaya
and Ammar Askar in :issue:`43950`.)
Other Language Changes
======================
* Asynchronous comprehensions are now allowed inside comprehensions in
asynchronous functions. Outer comprehensions implicitly become
asynchronous. (Contributed by Serhiy Storchaka in :issue:`33346`.)
* A :exc:`TypeError` is now raised instead of an :exc:`AttributeError` in
:meth:`contextlib.ExitStack.enter_context` and
:meth:`contextlib.AsyncExitStack.enter_async_context` for objects which do not
support the :term:`context manager` or :term:`asynchronous context manager`
protocols correspondingly.
(Contributed by Serhiy Storchaka in :issue:`44471`.)
* A :exc:`TypeError` is now raised instead of an :exc:`AttributeError` in
:keyword:`with` and :keyword:`async with` statements for objects which do not
support the :term:`context manager` or :term:`asynchronous context manager`
protocols correspondingly.
(Contributed by Serhiy Storchaka in :issue:`12022`.)
Other CPython Implementation Changes
====================================
* Special methods :meth:`complex.__complex__` and :meth:`bytes.__bytes__` are implemented to
support :class:`typing.SupportsComplex` and :class:`typing.SupportsBytes` protocols.
(Contributed by Mark Dickinson and Dong-hee Na in :issue:`24234`.)
* ``siphash13`` is added as a new internal hashing algorithms. It's has similar security
properties as ``siphash24`` but it is slightly faster for long inputs. ``str``, ``bytes``,
and some other types now use it as default algorithm for ``hash()``. :pep:`552`
hash-based pyc files now use ``siphash13``, too.
(Contributed by Inada Naoki in :issue:`29410`.)
New Modules
===========
* None yet.
Improved Modules
================
fractions
---------
* Support :PEP:`515`-style initialization of :class:`~fractions.Fraction` from
string. (Contributed by Sergey B Kirpichev in :issue:`44258`.)
* :class:`~fractions.Fraction` now implements an ``__int__`` method, so
that an ``isinstance(some_fraction, typing.SupportsInt)`` check passes.
(Contributed by Mark Dickinson in :issue:`44547`.)
math
----
* Add :func:`math.cbrt`: return the cube root of x.
(Contributed by Ajith Ramachandran in :issue:`44357`.)
* The behaviour of two :func:`math.pow` corner cases was changed, for
consistency with the IEEE 754 specification. The operations
``math.pow(0.0, -math.inf)`` and ``math.pow(-0.0, -math.inf)`` now return
``inf``. Previously they raised :exc:`ValueError`. (Contributed by Mark
Dickinson in :issue:`44339`.)
operator
--------
* A new function ``operator.call`` has been added, such that
``operator.call(obj, *args, **kwargs) == obj(*args, **kwargs)``.
(Contributed by Antony Lee in :issue:`44019`.)
os
--
* On Windows, :func:`os.urandom` now uses ``BCryptGenRandom()``,
instead of ``CryptGenRandom()`` which is deprecated.
(Contributed by Dong-hee Na in :issue:`44611`.)
sqlite3
-------
* You can now disable the authorizer by passing :const:`None` to
:meth:`~sqlite3.Connection.set_authorizer`.
(Contributed by Erlend E. Aasland in :issue:`44491`.)
* Collation name :meth:`~sqlite3.Connection.create_collation` can now
contain any Unicode character. Collation names with invalid characters
now raise :exc:`UnicodeEncodeError` instead of :exc:`sqlite3.ProgrammingError`.
(Contributed by Erlend E. Aasland in :issue:`44688`.)
* :mod:`sqlite3` exceptions now include the SQLite extended error code as
:attr:`~sqlite3.Error.sqlite_errorcode` and the SQLite error name as
:attr:`~sqlite3.Error.sqlite_errorname`.
(Contributed by Aviv Palivoda, Daniel Shahaf, and Erlend E. Aasland in
:issue:`16379` and :issue:`24139`.)
* Add :meth:`~sqlite3.Connection.setlimit` and
:meth:`~sqlite3.Connection.getlimit` to :class:`sqlite3.Connection` for
setting and getting SQLite limits by connection basis.
(Contributed by Erlend E. Aasland in :issue:`45243`.)
* :mod:`sqlite3` now sets :attr:`sqlite3.threadsafety` based on the default
threading mode the underlying SQLite library has been compiled with.
(Contributed by Erlend E. Aasland in :issue:`45613`.)
threading
---------
* On Unix, if the ``sem_clockwait()`` function is available in the C library
(glibc 2.30 and newer), the :meth:`threading.Lock.acquire` method now uses
the monotonic clock (:data:`time.CLOCK_MONOTONIC`) for the timeout, rather
than using the system clock (:data:`time.CLOCK_REALTIME`), to not be affected
by system clock changes.
(Contributed by Victor Stinner in :issue:`41710`.)
time
----
* On Unix, :func:`time.sleep` now uses the ``clock_nanosleep()`` or
``nanosleep()`` function, if available, which has a resolution of 1 nanosecond
(10\ :sup:`-9` seconds), rather than using ``select()`` which has a resolution
of 1 microsecond (10\ :sup:`-6` seconds).
(Contributed by Benjamin Szőke and Victor Stinner in :issue:`21302`.)
* On Windows 8.1 and newer, :func:`time.sleep` now uses a waitable timer based
on `high-resolution timers
<https://docs.microsoft.com/en-us/windows-hardware/drivers/kernel/high-resolution-timers>`_
which has a resolution of 100 nanoseconds (10\ :sup:`-7` seconds). Previously,
it had a resolution of 1 millisecond (10\ :sup:`-3` seconds).
(Contributed by Benjamin Szőke, Dong-hee Na, Eryk Sun and Victor Stinner in :issue:`21302` and :issue:`45429`.)
unicodedata
-----------
* The Unicode database has been updated to version 14.0.0. (:issue:`45190`).
Optimizations
=============
* Compiler now optimizes simple C-style formatting with literal format
containing only format codes ``%s``, ``%r`` and ``%a`` and makes it as
fast as corresponding f-string expression.
(Contributed by Serhiy Storchaka in :issue:`28307`.)
* "Zero-cost" exceptions are implemented. The cost of ``try`` statements is
almost eliminated when no exception is raised.
(Contributed by Mark Shannon in :issue:`40222`.)
* Method calls with keywords are now faster due to bytecode
changes which avoid creating bound method instances. Previously, this
optimization was applied only to method calls with purely positional
arguments.
(Contributed by Ken Jin and Mark Shannon in :issue:`26110`, based on ideas
implemented in PyPy.)
* Pure ASCII strings are now normalized in constant time by :func:`unicodedata.normalize`.
(Contributed by Dong-hee Na in :issue:`44987`.)
CPython bytecode changes
========================
* Replaced all numeric ``BINARY_*`` and ``INPLACE_*`` instructions with a single
:opcode:`BINARY_OP` implementation.
* Added a new :opcode:`CALL_METHOD_KW` opcode. Calls a method in a similar
fashion as :opcode:`CALL_METHOD`, but also supports keyword arguments. Works
in tandem with :opcode:`LOAD_METHOD`.
* Removed ``COPY_DICT_WITHOUT_KEYS``.
* :opcode:`MATCH_CLASS` and :opcode:`MATCH_KEYS` no longer push an additional
boolean value indicating whether the match succeeded or failed. Instead, they
indicate failure with :const:`None` (where a tuple of extracted values would
otherwise be).
* Added :opcode:`COPY`, which pushes the *i*-th item to the top of the stack.
The item is not removed from its original location.
* :opcode:`JUMP_IF_NOT_EXC_MATCH` no longer pops the active exception.
Deprecated
==========
* The :mod:`lib2to3` package and ``2to3`` tool are now deprecated and may not
be able to parse Python 3.10 or newer. See the :pep:`617` (New PEG parser for
CPython). (Contributed by Victor Stinner in :issue:`40360`.)
* :class:`webbrowser.MacOSX` is deprecated and will be removed in Python 3.13.
It is untested and undocumented and also not used by webbrowser itself.
(Contributed by Dong-hee Na in :issue:`42255`.)
* The behavior of returning a value from a :class:`~unittest.TestCase` and
:class:`~unittest.IsolatedAsyncioTestCase` test methods (other than the
default ``None`` value), is now deprecated.
* Deprecated the following :mod:`unittest` functions, scheduled for removal in
Python 3.13:
* :func:`unittest.findTestCases`
* :func:`unittest.makeSuite`
* :func:`unittest.getTestCaseNames`
Use :class:`~unittest.TestLoader` method instead:
* :meth:`unittest.TestLoader.loadTestsFromModule`
* :meth:`unittest.TestLoader.loadTestsFromTestCase`
* :meth:`unittest.TestLoader.getTestCaseNames`
(Contributed by Erlend E. Aasland in :issue:`5846`.)
* The :meth:`turtle.RawTurtle.settiltangle` is deprecated since Python 3.1,
it now emits a deprecation warning and will be removed in Python 3.13. Use
:meth:`turtle.RawTurtle.tiltangle` instead (it was earlier incorrectly marked
as deprecated, its docstring is now corrected).
(Contributed by Hugo van Kemenade in :issue:`45837`.)
Removed
=======
* :class:`smtpd.MailmanProxy` is now removed as it is unusable without
an external module, ``mailman``. (Contributed by Dong-hee Na in :issue:`35800`.)
* The ``binhex`` module, deprecated in Python 3.9, is now removed.
The following :mod:`binascii` functions, deprecated in Python 3.9, are now
also removed:
* ``a2b_hqx()``, ``b2a_hqx()``;
* ``rlecode_hqx()``, ``rledecode_hqx()``.
The :func:`binascii.crc_hqx` function remains available.
(Contributed by Victor Stinner in :issue:`45085`.)
* The distutils ``bdist_msi`` command, deprecated in Python 3.9, is now removed.
Use ``bdist_wheel`` (wheel packages) instead.
(Contributed by Hugo van Kemenade in :issue:`45124`.)
* Due to significant security concerns, the *reuse_address* parameter of
:meth:`asyncio.loop.create_datagram_endpoint`, disabled in Python 3.9, is
now entirely removed. This is because of the behavior of the socket option
``SO_REUSEADDR`` in UDP.
(Contributed by Hugo van Kemenade in :issue:`45129`.)
* Removed :meth:`__getitem__` methods of
:class:`xml.dom.pulldom.DOMEventStream`, :class:`wsgiref.util.FileWrapper`
and :class:`fileinput.FileInput`, deprecated since Python 3.9.
(Contributed by Hugo van Kemenade in :issue:`45132`.)
* Removed many old deprecated :mod:`unittest` features:
- :class:`~unittest.TestCase` method aliases ``failUnlessEqual``,
``failIfEqual``, ``failUnless``, ``failIf``, ``failUnlessRaises``,
``failUnlessAlmostEqual``, ``failIfAlmostEqual`` (deprecated in Python 3.1),
``assertEquals``, ``assertNotEquals``, ``assert_``, ``assertAlmostEquals``,
``assertNotAlmostEquals``, ``assertRegexpMatches``, ``assertRaisesRegexp``
(deprecated in Python 3.2), and ``assertNotRegexpMatches`` (deprecated in
Python 3.5).
- Undocumented and broken :class:`~unittest.TestCase` method
``assertDictContainsSubset`` (deprecated in Python 3.2).
- Undocumented :meth:`<unittest.TestLoader.loadTestsFromModule>
TestLoader.loadTestsFromModule` parameter *use_load_tests* (deprecated
and ignored since Python 3.2).
- An alias of the :class:`~unittest.TextTestResult` class:
``_TextTestResult`` (deprecated in Python 3.2).
(Contributed by Serhiy Storchaka in :issue:`45162`.)
* The following deprecated functions and methods are removed in the :mod:`gettext`
module: :func:`~gettext.lgettext`, :func:`~gettext.ldgettext`,
:func:`~gettext.lngettext` and :func:`~gettext.ldngettext`.
Function :func:`~gettext.bind_textdomain_codeset`, methods
:meth:`~gettext.NullTranslations.output_charset` and
:meth:`~gettext.NullTranslations.set_output_charset`, and the *codeset*
parameter of functions :func:`~gettext.translation` and
:func:`~gettext.install` are also removed, since they are only used for
the ``l*gettext()`` functions.
(Contributed by Dong-hee Na and Serhiy Storchaka in :issue:`44235`.)
* Removed from the :mod:`configparser` module:
the :class:`SafeConfigParser` class,
the :attr:`filename` property of the :class:`ParsingError` class,
the :meth:`readfp` method of the :class:`ConfigParser` class,
deprecated since Python 3.2.
(Contributed by Hugo van Kemenade in :issue:`45173`.)
* The :func:`@asyncio.coroutine <asyncio.coroutine>` :term:`decorator` enabling
legacy generator-based coroutines to be compatible with async/await code.
The function has been deprecated since Python 3.8 and the removal was
initially scheduled for Python 3.10. Use :keyword:`async def` instead.
(Contributed by Illia Volochii in :issue:`43216`.)
* :class:`asyncio.coroutines.CoroWrapper` used for wrapping legacy
generator-based coroutine objects in the debug mode.
(Contributed by Illia Volochii in :issue:`43216`.)
* Removed the deprecated ``split()`` method of :class:`_tkinter.TkappType`.
(Contributed by Erlend E. Aasland in :issue:`38371`.)
* Removed from the :mod:`inspect` module:
* the ``getargspec`` function, deprecated since Python 3.0;
use :func:`inspect.signature` or :func:`inspect.getfullargspec` instead.
* the ``formatargspec`` function, deprecated since Python 3.5;
use the :func:`inspect.signature` function and :class:`Signature` object
directly.
* the undocumented ``Signature.from_callable`` and ``Signature.from_function``
functions, deprecated since Python 3.5; use the
:meth:`Signature.from_callable() <inspect.Signature.from_callable>` method
instead.
(Contributed by Hugo van Kemenade in :issue:`45320`.)
* Remove the ``asyncore`` and ``asynchat`` modules, deprecated in Python 3.6:
use the :mod:`asyncio` module instead.
(Contributed by Victor Stinner in :issue:`28533`.)
* Remove the ``smtpd`` module, deprecated in Python 3.6: the `aiosmtpd
<https://aiosmtpd.readthedocs.io/>`__ module can be used instead, it is based
on asyncio.
(Contributed by Victor Stinner in :issue:`28533`.)
Porting to Python 3.11
======================
This section lists previously described changes and other bugfixes
that may require changes to your code.
Changes in the Python API
-------------------------
* Prohibited passing non-:class:`concurrent.futures.ThreadPoolExecutor`
executors to :meth:`loop.set_default_executor` following a deprecation in
Python 3.8.
(Contributed by Illia Volochii in :issue:`43234`.)
* :func:`open`, :func:`io.open`, :func:`codecs.open` and
:class:`fileinput.FileInput` no longer accept ``'U'`` ("universal newline")
in the file mode. This flag was deprecated since Python 3.3. In Python 3, the
"universal newline" is used by default when a file is open in text mode. The
:ref:`newline parameter <open-newline-parameter>` of :func:`open` controls
how universal newlines works.
(Contributed by Victor Stinner in :issue:`37330`.)
* The :mod:`pdb` module now reads the :file:`.pdbrc` configuration file with
the ``'utf-8'`` encoding.
(Contributed by Srinivas Reddy Thatiparthy (శ్రీనివాస్ రెడ్డి తాటిపర్తి) in :issue:`41137`.)
* When sorting using tuples as keys, the order of the result may differ
from earlier releases if the tuple elements don't define a total
ordering (see :ref:`expressions-value-comparisons` for
information on total ordering). It's generally true that the result
of sorting simply isn't well-defined in the absence of a total ordering
on list elements.
Build Changes
=============
* CPython can now be built with the ThinLTO option via ``--with-lto=thin``.
(Contributed by Dong-hee Na and Brett Holman in :issue:`44340`.)
* libpython is no longer linked against libcrypt.
(Contributed by Mike Gilbert in :issue:`45433`.)
* Building Python now requires a C99 ``<math.h>`` header file providing
the following functions: ``copysign()``, ``hypot()``, ``isfinite()``,
``isinf()``, ``isnan()``, ``round()``.
(Contributed by Victor Stinner in :issue:`45440`.)
* Freelists for object structs can now be disabled. A new :program:`configure`
option :option:`!--without-freelists` can be used to disable all freelists
except empty tuple singleton.
(Contributed by Christian Heimes in :issue:`45522`)
* ``Modules/Setup`` and ``Modules/makesetup`` have been improved and tied up.
Extension modules can now be built through ``makesetup``. All except some
test modules can be linked statically into main binary or library.
(Contributed by Brett Cannon and Christian Heimes in :issue:`45548`,
:issue:`45570`, :issue:`45571`, and :issue:`43974`.)
* The build dependencies for :mod:`zlib`, :mod:`bz2`, and :mod:`lzma` are now
detected by :program:`configure`.
(Contributed by Christian Heimes in :issue:`45763`.)
* Build dependencies for :mod:`dbm` are now detected by :program:`configure`.
``libdb`` 3.x and 4.x are no longer supported.
(Contributed by Christian Heimes in :issue:`45747`.)
C API Changes
=============
New Features
------------
* Add a new :c:func:`PyType_GetName` function to get type's short name.
(Contributed by Hai Shi in :issue:`42035`.)
* Add a new :c:func:`PyType_GetQualName` function to get type's qualified name.
(Contributed by Hai Shi in :issue:`42035`.)
* Add new :c:func:`PyThreadState_EnterTracing` and
:c:func:`PyThreadState_LeaveTracing` functions to the limited C API to
suspend and resume tracing and profiling.
(Contributed by Victor Stinner in :issue:`43760`.)
Porting to Python 3.11
----------------------
* The old trashcan macros (``Py_TRASHCAN_SAFE_BEGIN``/``Py_TRASHCAN_SAFE_END``)
are now deprecated. They should be replaced by the new macros
``Py_TRASHCAN_BEGIN`` and ``Py_TRASHCAN_END``.
A tp_dealloc function that has the old macros, such as::
static void
mytype_dealloc(mytype *p)
{
PyObject_GC_UnTrack(p);
Py_TRASHCAN_SAFE_BEGIN(p);
...
Py_TRASHCAN_SAFE_END
}
should migrate to the new macros as follows::
static void
mytype_dealloc(mytype *p)
{
PyObject_GC_UnTrack(p);
Py_TRASHCAN_BEGIN(p, mytype_dealloc)
...
Py_TRASHCAN_END
}
Note that ``Py_TRASHCAN_BEGIN`` has a second argument which
should be the deallocation function it is in.
To support older Python versions in the same codebase, you
can define the following macros and use them throughout
the code (credit: these were copied from the ``mypy`` codebase)::
#if PY_MAJOR_VERSION >= 3 && PY_MINOR_VERSION >= 8
# define CPy_TRASHCAN_BEGIN(op, dealloc) Py_TRASHCAN_BEGIN(op, dealloc)
# define CPy_TRASHCAN_END(op) Py_TRASHCAN_END
#else
# define CPy_TRASHCAN_BEGIN(op, dealloc) Py_TRASHCAN_SAFE_BEGIN(op)
# define CPy_TRASHCAN_END(op) Py_TRASHCAN_SAFE_END(op)
#endif
* The :c:func:`PyType_Ready` function now raises an error if a type is defined
with the :const:`Py_TPFLAGS_HAVE_GC` flag set but has no traverse function
(:c:member:`PyTypeObject.tp_traverse`).
(Contributed by Victor Stinner in :issue:`44263`.)
* Heap types with the :const:`Py_TPFLAGS_IMMUTABLETYPE` flag can now inherit
the :pep:`590` vectorcall protocol. Previously, this was only possible for
:ref:`static types <static-types>`.
(Contributed by Erlend E. Aasland in :issue:`43908`)
* Since :c:func:`Py_TYPE()` is changed to a inline static function,
``Py_TYPE(obj) = new_type`` must be replaced with
``Py_SET_TYPE(obj, new_type)``: see the :c:func:`Py_SET_TYPE()` function
(available since Python 3.9). For backward compatibility, this macro can be
used::
#if PY_VERSION_HEX < 0x030900A4 && !defined(Py_SET_TYPE)
static inline void _Py_SET_TYPE(PyObject *ob, PyTypeObject *type)
{ ob->ob_type = type; }
#define Py_SET_TYPE(ob, type) _Py_SET_TYPE((PyObject*)(ob), type)
#endif
(Contributed by Victor Stinner in :issue:`39573`.)
* Since :c:func:`Py_SIZE()` is changed to a inline static function,
``Py_SIZE(obj) = new_size`` must be replaced with
``Py_SET_SIZE(obj, new_size)``: see the :c:func:`Py_SET_SIZE()` function
(available since Python 3.9). For backward compatibility, this macro can be
used::
#if PY_VERSION_HEX < 0x030900A4 && !defined(Py_SET_SIZE)
static inline void _Py_SET_SIZE(PyVarObject *ob, Py_ssize_t size)
{ ob->ob_size = size; }
#define Py_SET_SIZE(ob, size) _Py_SET_SIZE((PyVarObject*)(ob), size)
#endif
(Contributed by Victor Stinner in :issue:`39573`.)
* ``<Python.h>`` no longer includes the header files ``<stdlib.h>``,
``<stdio.h>``, ``<errno.h>`` and ``<string.h>`` when the ``Py_LIMITED_API``
macro is set to ``0x030b0000`` (Python 3.11) or higher. C extensions should
explicitly include the header files after ``#include <Python.h>``.
(Contributed by Victor Stinner in :issue:`45434`.)
* The non-limited API files ``cellobject.h``, ``classobject.h``, ``context.h``,
``funcobject.h``, ``genobject.h`` and ``longintrepr.h`` have been moved to
the ``Include/cpython`` directory. Moreover, the ``eval.h`` header file was
removed. These files must not be included directly, as they are already
included in ``Python.h``: :ref:`Include Files <api-includes>`. If they have
been included directly, consider including ``Python.h`` instead.
(Contributed by Victor Stinner in :issue:`35134`.)
Deprecated
----------
* Deprecate the following functions to configure the Python initialization:
* :c:func:`PySys_AddWarnOptionUnicode`
* :c:func:`PySys_AddWarnOption`
* :c:func:`PySys_AddXOption`
* :c:func:`PySys_HasWarnOptions`
* :c:func:`Py_SetPath`
* :c:func:`Py_SetProgramName`
* :c:func:`Py_SetPythonHome`
* :c:func:`Py_SetStandardStreamEncoding`
* :c:func:`_Py_SetProgramFullPath`
Use the new :c:type:`PyConfig` API of the :ref:`Python Initialization Configuration
<init-config>` instead (:pep:`587`).
(Contributed by Victor Stinner in :issue:`44113`.)
Removed
-------
* :c:func:`PyFrame_BlockSetup` and :c:func:`PyFrame_BlockPop` have been
removed.
(Contributed by Mark Shannon in :issue:`40222`.)
* Remove the following math macros using the ``errno`` variable:
* ``Py_ADJUST_ERANGE1()``
* ``Py_ADJUST_ERANGE2()``
* ``Py_OVERFLOWED()``
* ``Py_SET_ERANGE_IF_OVERFLOW()``
* ``Py_SET_ERRNO_ON_MATH_ERROR()``
(Contributed by Victor Stinner in :issue:`45412`.)
* Remove ``Py_UNICODE_COPY()`` and ``Py_UNICODE_FILL()`` macros, deprecated
since Python 3.3. Use ``PyUnicode_CopyCharacters()`` or ``memcpy()``
(``wchar_t*`` string), and ``PyUnicode_Fill()`` functions instead.
(Contributed by Victor Stinner in :issue:`41123`.)
* Remove the ``pystrhex.h`` header file. It only contains private functions.
C extensions should only include the main ``<Python.h>`` header file.
(Contributed by Victor Stinner in :issue:`45434`.)
* Remove the ``Py_FORCE_DOUBLE()`` macro. It was used by the
``Py_IS_INFINITY()`` macro.
(Contributed by Victor Stinner in :issue:`45440`.)
* The following items are no longer available when :c:macro:`Py_LIMITED_API`
is defined:
* :c:func:`PyMarshal_WriteLongToFile`
* :c:func:`PyMarshal_WriteObjectToFile`
* :c:func:`PyMarshal_ReadObjectFromString`
* :c:func:`PyMarshal_WriteObjectToString`
* the ``Py_MARSHAL_VERSION`` macro
These are not part of the :ref:`limited API <stable-abi-list>`.
(Contributed by Victor Stinner in :issue:`45474`.)
* Exclude :c:func:`PyWeakref_GET_OBJECT` from the limited C API. It never
worked since the :c:type:`PyWeakReference` structure is opaque in the
limited C API.
(Contributed by Victor Stinner in :issue:`35134`.)