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ReStructuredText
****************************
|
||
What's new in Python 3.14
|
||
****************************
|
||
|
||
:Editor: TBD
|
||
|
||
.. 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 issue number as a comment:
|
||
|
||
XXX Describe the transmogrify() function added to the socket
|
||
module.
|
||
(Contributed by P.Y. Developer in :gh:`12345`.)
|
||
|
||
This saves the maintainer the effort of going through the VCS log
|
||
when researching a change.
|
||
|
||
This article explains the new features in Python 3.14, compared to 3.13.
|
||
|
||
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 3.14 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 3.14.
|
||
Brevity is key.
|
||
|
||
|
||
.. PEP-sized items next.
|
||
|
||
* :ref:`PEP 649: deferred evaluation of annotations <whatsnew314-pep649>`
|
||
* :ref:`PEP 741: Python Configuration C API <whatsnew314-pep741>`
|
||
* :ref:`PEP 750: Template Strings <whatsnew314-pep750>`
|
||
* :ref:`PEP 758: Allow except and except* expressions without parentheses <whatsnew314-pep758>`
|
||
* :ref:`PEP 761: Discontinuation of PGP signatures <whatsnew314-pep761>`
|
||
* :ref:`PEP 765: Disallow return/break/continue that exit a finally block <whatsnew314-pep765>`
|
||
* :ref:`PEP 768: Safe external debugger interface for CPython <whatsnew314-pep768>`
|
||
* :ref:`A new type of interpreter <whatsnew314-tail-call>`
|
||
|
||
|
||
Incompatible changes
|
||
====================
|
||
|
||
On platforms other than macOS and Windows, the default :ref:`start
|
||
method <multiprocessing-start-methods>` for :mod:`multiprocessing`
|
||
and :class:`~concurrent.futures.ProcessPoolExecutor` switches from
|
||
*fork* to *forkserver*.
|
||
|
||
See :ref:`(1) <whatsnew314-concurrent-futures-start-method>` and
|
||
:ref:`(2) <whatsnew314-multiprocessing-start-method>` for details.
|
||
|
||
If you encounter :exc:`NameError`\s or pickling errors coming out of
|
||
:mod:`multiprocessing` or :mod:`concurrent.futures`, see the
|
||
:ref:`forkserver restrictions <multiprocessing-programming-forkserver>`.
|
||
|
||
The interpreter avoids some reference count modifications internally when
|
||
it's safe to do so. This can lead to different values returned from
|
||
:func:`sys.getrefcount` and :c:func:`Py_REFCNT` compared to previous versions
|
||
of Python. See :ref:`below <whatsnew314-refcount>` for details.
|
||
|
||
New features
|
||
============
|
||
|
||
.. _whatsnew314-pep750:
|
||
|
||
PEP 750: Template Strings
|
||
-------------------------
|
||
|
||
Template string literals (t-strings) are a generalization of f-strings,
|
||
using a ``t`` in place of the ``f`` prefix. Instead of evaluating
|
||
to :class:`str`, t-strings evaluate to a new :class:`!string.templatelib.Template` type:
|
||
|
||
.. code-block:: python
|
||
|
||
from string.templatelib import Template
|
||
|
||
name = "World"
|
||
template: Template = t"Hello {name}"
|
||
|
||
The template can then be combined with functions that operate on the template's
|
||
structure to produce a :class:`str` or a string-like result.
|
||
For example, sanitizing input:
|
||
|
||
.. code-block:: python
|
||
|
||
evil = "<script>alert('evil')</script>"
|
||
template = t"<p>{evil}</p>"
|
||
assert html(template) == "<p><script>alert('evil')</script></p>"
|
||
|
||
As another example, generating HTML attributes from data:
|
||
|
||
.. code-block:: python
|
||
|
||
attributes = {"src": "shrubbery.jpg", "alt": "looks nice"}
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||
template = t"<img {attributes} />"
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||
assert html(template) == '<img src="shrubbery.jpg" alt="looks nice" class="looks-nice" />'
|
||
|
||
Unlike f-strings, the ``html`` function has access to template attributes
|
||
containing the original information: static strings, interpolations, and values
|
||
from the original scope. Unlike existing templating approaches, t-strings build
|
||
from the well-known f-string syntax and rules. Template systems thus benefit
|
||
from Python tooling as they are much closer to the Python language, syntax,
|
||
scoping, and more.
|
||
|
||
Writing template handlers is straightforward:
|
||
|
||
.. code-block:: python
|
||
|
||
from string.templatelib import Template, Interpolation
|
||
|
||
def lower_upper(template: Template) -> str:
|
||
"""Render static parts lowercased and interpolations uppercased."""
|
||
parts: list[str] = []
|
||
for item in template:
|
||
if isinstance(item, Interpolation):
|
||
parts.append(str(item.value).upper())
|
||
else:
|
||
parts.append(item.lower())
|
||
return "".join(parts)
|
||
|
||
name = "world"
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||
assert lower_upper(t"HELLO {name}") == "hello WORLD"
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||
|
||
With this in place, developers can write template systems to sanitize SQL, make
|
||
safe shell operations, improve logging, tackle modern ideas in web development
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||
(HTML, CSS, and so on), and implement lightweight, custom business DSLs.
|
||
|
||
See :pep:`750` for more details.
|
||
|
||
(Contributed by Jim Baker, Guido van Rossum, Paul Everitt, Koudai Aono,
|
||
Lysandros Nikolaou, Dave Peck, Adam Turner, Jelle Zijlstra, Bénédikt Tran,
|
||
and Pablo Galindo Salgado in :gh:`132661`.)
|
||
|
||
.. _whatsnew314-pep768:
|
||
|
||
PEP 768: Safe external debugger interface for CPython
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||
-----------------------------------------------------
|
||
|
||
:pep:`768` introduces a zero-overhead debugging interface that allows debuggers and profilers
|
||
to safely attach to running Python processes. This is a significant enhancement to Python's
|
||
debugging capabilities allowing debuggers to forego unsafe alternatives. See
|
||
:ref:`below <whatsnew314-remote-pdb>` for how this feature is leveraged to
|
||
implement the new :mod:`pdb` module's remote attaching capabilities.
|
||
|
||
The new interface provides safe execution points for attaching debugger code without modifying
|
||
the interpreter's normal execution path or adding runtime overhead. This enables tools to
|
||
inspect and interact with Python applications in real-time without stopping or restarting
|
||
them — a crucial capability for high-availability systems and production environments.
|
||
|
||
For convenience, CPython implements this interface through the :mod:`sys` module with a
|
||
:func:`sys.remote_exec` function::
|
||
|
||
sys.remote_exec(pid, script_path)
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||
|
||
This function allows sending Python code to be executed in a target process at the next safe
|
||
execution point. However, tool authors can also implement the protocol directly as described
|
||
in the PEP, which details the underlying mechanisms used to safely attach to running processes.
|
||
|
||
Here's a simple example that inspects object types in a running Python process:
|
||
|
||
.. code-block:: python
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||
|
||
import os
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||
import sys
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||
import tempfile
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||
|
||
# Create a temporary script
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||
with tempfile.NamedTemporaryFile(mode='w', suffix='.py', delete=False) as f:
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||
script_path = f.name
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||
f.write(f"import my_debugger; my_debugger.connect({os.getpid()})")
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||
try:
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||
# Execute in process with PID 1234
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||
print("Behold! An offering:")
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||
sys.remote_exec(1234, script_path)
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||
finally:
|
||
os.unlink(script_path)
|
||
|
||
The debugging interface has been carefully designed with security in mind and includes several
|
||
mechanisms to control access:
|
||
|
||
* A :envvar:`PYTHON_DISABLE_REMOTE_DEBUG` environment variable.
|
||
* A :option:`-X disable-remote-debug` command-line option.
|
||
* A :option:`--without-remote-debug` configure flag to completely disable the feature at build time.
|
||
|
||
A key implementation detail is that the interface piggybacks on the interpreter's existing evaluation
|
||
loop and safe points, ensuring zero overhead during normal execution while providing a reliable way
|
||
for external processes to coordinate debugging operations.
|
||
|
||
See :pep:`768` for more details.
|
||
|
||
(Contributed by Pablo Galindo Salgado, Matt Wozniski, and Ivona Stojanovic in :gh:`131591`.)
|
||
|
||
|
||
.. _whatsnew314-remote-pdb:
|
||
|
||
Remote attaching to a running Python process with PDB
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||
-----------------------------------------------------
|
||
|
||
The :mod:`pdb` module now supports remote attaching to a running Python process
|
||
using a new ``-p PID`` command-line option:
|
||
|
||
.. code-block:: sh
|
||
|
||
python -m pdb -p 1234
|
||
|
||
This will connect to the Python process with the given PID and allow you to
|
||
debug it interactively. Notice that due to how the Python interpreter works
|
||
attaching to a remote process that is blocked in a system call or waiting for
|
||
I/O will only work once the next bytecode instruction is executed or when the
|
||
process receives a signal.
|
||
|
||
This feature leverages :pep:`768` and the :func:`sys.remote_exec` function
|
||
to attach to the remote process and send the PDB commands to it.
|
||
|
||
|
||
(Contributed by Matt Wozniski and Pablo Galindo in :gh:`131591`.)
|
||
|
||
|
||
.. _whatsnew314-pep758:
|
||
|
||
PEP 758 – Allow except and except* expressions without parentheses
|
||
------------------------------------------------------------------
|
||
|
||
The :keyword:`except` and :keyword:`except* <except_star>` expressions now allow
|
||
parentheses to be omitted when there are multiple exception types and the ``as`` clause is not used.
|
||
For example the following expressions are now valid:
|
||
|
||
.. code-block:: python
|
||
|
||
try:
|
||
release_new_sleep_token_album()
|
||
except AlbumNotFound, SongsTooGoodToBeReleased:
|
||
print("Sorry, no new album this year.")
|
||
|
||
# The same applies to except* (for exception groups):
|
||
try:
|
||
release_new_sleep_token_album()
|
||
except* AlbumNotFound, SongsTooGoodToBeReleased:
|
||
print("Sorry, no new album this year.")
|
||
|
||
Check :pep:`758` for more details.
|
||
|
||
(Contributed by Pablo Galindo and Brett Cannon in :gh:`131831`.)
|
||
|
||
|
||
.. _whatsnew314-pep649:
|
||
|
||
PEP 649: deferred evaluation of annotations
|
||
-------------------------------------------
|
||
|
||
The :term:`annotations <annotation>` on functions, classes, and modules are no
|
||
longer evaluated eagerly. Instead, annotations are stored in special-purpose
|
||
:term:`annotate functions <annotate function>` and evaluated only when
|
||
necessary. This is specified in :pep:`649` and :pep:`749`.
|
||
|
||
This change is designed to make annotations in Python more performant and more
|
||
usable in most circumstances. The runtime cost for defining annotations is
|
||
minimized, but it remains possible to introspect annotations at runtime.
|
||
It is usually no longer necessary to enclose annotations in strings if they
|
||
contain forward references.
|
||
|
||
The new :mod:`annotationlib` module provides tools for inspecting deferred
|
||
annotations. Annotations may be evaluated in the :attr:`~annotationlib.Format.VALUE`
|
||
format (which evaluates annotations to runtime values, similar to the behavior in
|
||
earlier Python versions), the :attr:`~annotationlib.Format.FORWARDREF` format
|
||
(which replaces undefined names with special markers), and the
|
||
:attr:`~annotationlib.Format.STRING` format (which returns annotations as strings).
|
||
|
||
This example shows how these formats behave:
|
||
|
||
.. doctest::
|
||
|
||
>>> from annotationlib import get_annotations, Format
|
||
>>> def func(arg: Undefined):
|
||
... pass
|
||
>>> get_annotations(func, format=Format.VALUE)
|
||
Traceback (most recent call last):
|
||
...
|
||
NameError: name 'Undefined' is not defined
|
||
>>> get_annotations(func, format=Format.FORWARDREF)
|
||
{'arg': ForwardRef('Undefined', owner=<function func at 0x...>)}
|
||
>>> get_annotations(func, format=Format.STRING)
|
||
{'arg': 'Undefined'}
|
||
|
||
Implications for annotated code
|
||
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
||
|
||
If you define annotations in your code (for example, for use with a static type
|
||
checker), then this change probably does not affect you: you can keep
|
||
writing annotations the same way you did with previous versions of Python.
|
||
|
||
You will likely be able to remove quoted strings in annotations, which are frequently
|
||
used for forward references. Similarly, if you use ``from __future__ import annotations``
|
||
to avoid having to write strings in annotations, you may well be able to
|
||
remove that import. However, if you rely on third-party libraries that read annotations,
|
||
those libraries may need changes to support unquoted annotations before they
|
||
work as expected.
|
||
|
||
Implications for readers of ``__annotations__``
|
||
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
||
|
||
If your code reads the ``__annotations__`` attribute on objects, you may want
|
||
to make changes in order to support code that relies on deferred evaluation of
|
||
annotations. For example, you may want to use :func:`annotationlib.get_annotations`
|
||
with the :attr:`~annotationlib.Format.FORWARDREF` format, as the :mod:`dataclasses`
|
||
module now does.
|
||
|
||
Related changes
|
||
^^^^^^^^^^^^^^^
|
||
|
||
The changes in Python 3.14 are designed to rework how ``__annotations__``
|
||
works at runtime while minimizing breakage to code that contains
|
||
annotations in source code and to code that reads ``__annotations__``. However,
|
||
if you rely on undocumented details of the annotation behavior or on private
|
||
functions in the standard library, there are many ways in which your code may
|
||
not work in Python 3.14. To safeguard your code against future changes,
|
||
use only the documented functionality of the :mod:`annotationlib` module.
|
||
|
||
``from __future__ import annotations``
|
||
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
||
|
||
In Python 3.7, :pep:`563` introduced the ``from __future__ import annotations``
|
||
directive, which turns all annotations into strings. This directive is now
|
||
considered deprecated and it is expected to be removed in a future version of Python.
|
||
However, this removal will not happen until after Python 3.13, the last version of
|
||
Python without deferred evaluation of annotations, reaches its end of life in 2029.
|
||
In Python 3.14, the behavior of code using ``from __future__ import annotations``
|
||
is unchanged.
|
||
|
||
|
||
Improved error messages
|
||
-----------------------
|
||
|
||
* The interpreter now provides helpful suggestions when it detects typos in Python
|
||
keywords. When a word that closely resembles a Python keyword is encountered,
|
||
the interpreter will suggest the correct keyword in the error message. This
|
||
feature helps programmers quickly identify and fix common typing mistakes. For
|
||
example:
|
||
|
||
.. code-block:: python
|
||
|
||
>>> whille True:
|
||
... pass
|
||
Traceback (most recent call last):
|
||
File "<stdin>", line 1
|
||
whille True:
|
||
^^^^^^
|
||
SyntaxError: invalid syntax. Did you mean 'while'?
|
||
|
||
>>> asynch def fetch_data():
|
||
... pass
|
||
Traceback (most recent call last):
|
||
File "<stdin>", line 1
|
||
asynch def fetch_data():
|
||
^^^^^^
|
||
SyntaxError: invalid syntax. Did you mean 'async'?
|
||
|
||
>>> async def foo():
|
||
... awaid fetch_data()
|
||
Traceback (most recent call last):
|
||
File "<stdin>", line 2
|
||
awaid fetch_data()
|
||
^^^^^
|
||
SyntaxError: invalid syntax. Did you mean 'await'?
|
||
|
||
>>> raisee ValueError("Error")
|
||
Traceback (most recent call last):
|
||
File "<stdin>", line 1
|
||
raisee ValueError("Error")
|
||
^^^^^^
|
||
SyntaxError: invalid syntax. Did you mean 'raise'?
|
||
|
||
While the feature focuses on the most common cases, some variations of
|
||
misspellings may still result in regular syntax errors.
|
||
(Contributed by Pablo Galindo in :gh:`132449`.)
|
||
|
||
* When unpacking assignment fails due to incorrect number of variables, the
|
||
error message prints the received number of values in more cases than before.
|
||
(Contributed by Tushar Sadhwani in :gh:`122239`.)
|
||
|
||
.. code-block:: python
|
||
|
||
>>> x, y, z = 1, 2, 3, 4
|
||
Traceback (most recent call last):
|
||
File "<stdin>", line 1, in <module>
|
||
x, y, z = 1, 2, 3, 4
|
||
^^^^^^^
|
||
ValueError: too many values to unpack (expected 3, got 4)
|
||
|
||
* :keyword:`elif` statements that follow an :keyword:`else` block now have a specific error message.
|
||
(Contributed by Steele Farnsworth in :gh:`129902`.)
|
||
|
||
.. code-block:: pycon
|
||
|
||
>>> if who == "me":
|
||
... print("It's me!")
|
||
... else:
|
||
... print("It's not me!")
|
||
... elif who is None:
|
||
... print("Who is it?")
|
||
File "<stdin>", line 5
|
||
elif who is None:
|
||
^^^^
|
||
SyntaxError: 'elif' block follows an 'else' block
|
||
|
||
* If a statement (:keyword:`pass`, :keyword:`del`, :keyword:`return`,
|
||
:keyword:`yield`, :keyword:`raise`, :keyword:`break`, :keyword:`continue`,
|
||
:keyword:`assert`, :keyword:`import`, :keyword:`from`) is passed to the
|
||
:ref:`if_expr` after :keyword:`else`, or one of :keyword:`pass`,
|
||
:keyword:`break`, or :keyword:`continue` is passed before :keyword:`if`, then the
|
||
error message highlights where the :token:`~python-grammar:expression` is
|
||
required. (Contributed by Sergey Miryanov in :gh:`129515`.)
|
||
|
||
.. code-block:: pycon
|
||
|
||
>>> x = 1 if True else pass
|
||
Traceback (most recent call last):
|
||
File "<string>", line 1
|
||
x = 1 if True else pass
|
||
^^^^
|
||
SyntaxError: expected expression after 'else', but statement is given
|
||
|
||
>>> x = continue if True else break
|
||
Traceback (most recent call last):
|
||
File "<string>", line 1
|
||
x = continue if True else break
|
||
^^^^^^^^
|
||
SyntaxError: expected expression before 'if', but statement is given
|
||
|
||
|
||
* When incorrectly closed strings are detected, the error message suggests
|
||
that the string may be intended to be part of the string. (Contributed by
|
||
Pablo Galindo in :gh:`88535`.)
|
||
|
||
.. code-block:: python
|
||
|
||
>>> "The interesting object "The important object" is very important"
|
||
Traceback (most recent call last):
|
||
SyntaxError: invalid syntax. Is this intended to be part of the string?
|
||
|
||
|
||
.. _whatsnew314-pep741:
|
||
|
||
PEP 741: Python Configuration C API
|
||
-----------------------------------
|
||
|
||
Add a :ref:`PyInitConfig C API <pyinitconfig_api>` to configure the Python
|
||
initialization without relying on C structures and the ability to make
|
||
ABI-compatible changes in the future.
|
||
|
||
Complete the :pep:`587` :ref:`PyConfig C API <pyconfig_api>` by adding
|
||
:c:func:`PyInitConfig_AddModule` which can be used to add a built-in extension
|
||
module; feature previously referred to as the “inittab”.
|
||
|
||
Add :c:func:`PyConfig_Get` and :c:func:`PyConfig_Set` functions to get and set
|
||
the current runtime configuration.
|
||
|
||
PEP 587 “Python Initialization Configuration” unified all the ways to configure
|
||
the Python initialization. This PEP unifies also the configuration of the
|
||
Python preinitialization and the Python initialization in a single API.
|
||
Moreover, this PEP only provides a single choice to embed Python, instead of
|
||
having two “Python” and “Isolated” choices (PEP 587), to simplify the API
|
||
further.
|
||
|
||
The lower level PEP 587 PyConfig API remains available for use cases with an
|
||
intentionally higher level of coupling to CPython implementation details (such
|
||
as emulating the full functionality of CPython’s CLI, including its
|
||
configuration mechanisms).
|
||
|
||
(Contributed by Victor Stinner in :gh:`107954`.)
|
||
|
||
.. seealso::
|
||
:pep:`741`.
|
||
|
||
.. _whatsnew314-tail-call:
|
||
|
||
A new type of interpreter
|
||
-------------------------
|
||
|
||
A new type of interpreter has been added to CPython.
|
||
It uses tail calls between small C functions that implement individual
|
||
Python opcodes, rather than one large C case statement.
|
||
For certain newer compilers, this interpreter provides
|
||
significantly better performance. Preliminary numbers on our machines suggest
|
||
anywhere up to 30% faster Python code, and a geometric mean of 3-5%
|
||
faster on ``pyperformance`` depending on platform and architecture. The
|
||
baseline is Python 3.14 built with Clang 19 without this new interpreter.
|
||
|
||
This interpreter currently only works with Clang 19 and newer
|
||
on x86-64 and AArch64 architectures. However, we expect
|
||
that a future release of GCC will support this as well.
|
||
|
||
This feature is opt-in for now. We highly recommend enabling profile-guided
|
||
optimization with the new interpreter as it is the only configuration we have
|
||
tested and can validate its improved performance.
|
||
For further information on how to build Python, see
|
||
:option:`--with-tail-call-interp`.
|
||
|
||
.. note::
|
||
|
||
This is not to be confused with `tail call optimization`__ of Python
|
||
functions, which is currently not implemented in CPython.
|
||
|
||
This new interpreter type is an internal implementation detail of the CPython
|
||
interpreter. It doesn't change the visible behavior of Python programs at
|
||
all. It can improve their performance, but doesn't change anything else.
|
||
|
||
__ https://en.wikipedia.org/wiki/Tail_call
|
||
|
||
.. attention::
|
||
|
||
This section previously reported a 9-15% geometric mean speedup. This number has since been
|
||
cautiously revised down to 3-5%. While we expect performance results to be better
|
||
than what we report, our estimates are more conservative due to a
|
||
`compiler bug <https://github.com/llvm/llvm-project/issues/106846>`_ found in
|
||
Clang/LLVM 19, which causes the normal interpreter to be slower. We were unaware of this bug,
|
||
resulting in inaccurate results. We sincerely apologize for
|
||
communicating results that were only accurate for LLVM v19.1.x and v20.1.0. In the meantime,
|
||
the bug has been fixed in LLVM v20.1.1 and for the upcoming v21.1, but it will remain
|
||
unfixed for LLVM v19.1.x and v20.1.0. Thus
|
||
any benchmarks with those versions of LLVM may produce inaccurate numbers.
|
||
(Thanks to Nelson Elhage for bringing this to light.)
|
||
|
||
(Contributed by Ken Jin in :gh:`128563`, with ideas on how to implement this
|
||
in CPython by Mark Shannon, Garrett Gu, Haoran Xu, and Josh Haberman.)
|
||
|
||
Syntax highlighting in PyREPL
|
||
-----------------------------
|
||
|
||
The default :term:`interactive` shell now highlights Python syntax as you
|
||
type. The feature is enabled by default unless the
|
||
:envvar:`PYTHON_BASIC_REPL` environment is set or any color-disabling
|
||
environment variables are used. See :ref:`using-on-controlling-color` for
|
||
details.
|
||
|
||
The default color theme for syntax highlighting strives for good contrast
|
||
and uses exclusively the 4-bit VGA standard ANSI color codes for maximum
|
||
compatibility. The theme can be customized using an experimental API
|
||
``_colorize.set_theme()``. This can be called interactively, as well as
|
||
in the :envvar:`PYTHONSTARTUP` script.
|
||
|
||
(Contributed by Łukasz Langa in :gh:`131507`.)
|
||
|
||
|
||
Other language changes
|
||
======================
|
||
|
||
* The :func:`map` built-in now has an optional keyword-only *strict* flag
|
||
like :func:`zip` to check that all the iterables are of equal length.
|
||
(Contributed by Wannes Boeykens in :gh:`119793`.)
|
||
|
||
* Incorrect usage of :keyword:`await` and asynchronous comprehensions
|
||
is now detected even if the code is optimized away by the :option:`-O`
|
||
command-line option. For example, ``python -O -c 'assert await 1'``
|
||
now produces a :exc:`SyntaxError`. (Contributed by Jelle Zijlstra in :gh:`121637`.)
|
||
|
||
* Writes to ``__debug__`` are now detected even if the code is optimized
|
||
away by the :option:`-O` command-line option. For example,
|
||
``python -O -c 'assert (__debug__ := 1)'`` now produces a
|
||
:exc:`SyntaxError`. (Contributed by Irit Katriel in :gh:`122245`.)
|
||
|
||
* Add class methods :meth:`float.from_number` and :meth:`complex.from_number`
|
||
to convert a number to :class:`float` or :class:`complex` type correspondingly.
|
||
They raise an error if the argument is a string.
|
||
(Contributed by Serhiy Storchaka in :gh:`84978`.)
|
||
|
||
* Implement mixed-mode arithmetic rules combining real and complex numbers as
|
||
specified by C standards since C99.
|
||
(Contributed by Sergey B Kirpichev in :gh:`69639`.)
|
||
|
||
* All Windows code pages are now supported as "cpXXX" codecs on Windows.
|
||
(Contributed by Serhiy Storchaka in :gh:`123803`.)
|
||
|
||
* :class:`super` objects are now :mod:`pickleable <pickle>` and
|
||
:mod:`copyable <copy>`.
|
||
(Contributed by Serhiy Storchaka in :gh:`125767`.)
|
||
|
||
* The :class:`memoryview` type now supports subscription,
|
||
making it a :term:`generic type`.
|
||
(Contributed by Brian Schubert in :gh:`126012`.)
|
||
|
||
* 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`).
|
||
(Contributed by Sergey B Kirpichev in :gh:`87790`.)
|
||
|
||
* The :func:`bytes.fromhex` and :func:`bytearray.fromhex` methods now accept
|
||
ASCII :class:`bytes` and :term:`bytes-like objects <bytes-like object>`.
|
||
(Contributed by Daniel Pope in :gh:`129349`.)
|
||
|
||
* Support ``\z`` as a synonym for ``\Z`` in :mod:`regular expressions <re>`.
|
||
It is interpreted unambiguously in many other regular expression engines,
|
||
unlike ``\Z``, which has subtly different behavior.
|
||
(Contributed by Serhiy Storchaka in :gh:`133306`.)
|
||
|
||
* ``\B`` in :mod:`regular expression <re>` now matches empty input string.
|
||
Now it is always the opposite of ``\b``.
|
||
(Contributed by Serhiy Storchaka in :gh:`124130`.)
|
||
|
||
* iOS and macOS apps can now be configured to redirect ``stdout`` and
|
||
``stderr`` content to the system log. (Contributed by Russell Keith-Magee in
|
||
:gh:`127592`.)
|
||
|
||
* The iOS testbed is now able to stream test output while the test is running.
|
||
The testbed can also be used to run the test suite of projects other than
|
||
CPython itself. (Contributed by Russell Keith-Magee in :gh:`127592`.)
|
||
|
||
* Three-argument :func:`pow` now try calling :meth:`~object.__rpow__` if necessary.
|
||
Previously it was only called in two-argument :func:`!pow` and the binary
|
||
power operator.
|
||
(Contributed by Serhiy Storchaka in :gh:`130104`.)
|
||
|
||
* Add a built-in implementation for HMAC (:rfc:`2104`) using formally verified
|
||
code from the `HACL* <https://github.com/hacl-star/hacl-star/>`__ project.
|
||
This implementation is used as a fallback when the OpenSSL implementation
|
||
of HMAC is not available.
|
||
(Contributed by Bénédikt Tran in :gh:`99108`.)
|
||
|
||
* When subclassing from a pure C type, the C slots for the new type are no
|
||
longer replaced with a wrapped version on class creation if they are not
|
||
explicitly overridden in the subclass.
|
||
(Contributed by Tomasz Pytel in :gh:`132329`.)
|
||
|
||
* The command line option :option:`-c` now automatically dedents its code
|
||
argument before execution. The auto-dedentation behavior mirrors
|
||
:func:`textwrap.dedent`.
|
||
(Contributed by Jon Crall and Steven Sun in :gh:`103998`.)
|
||
|
||
* Improve error message when an object supporting the synchronous (resp.
|
||
asynchronous) context manager protocol is entered using :keyword:`async
|
||
with` (resp. :keyword:`with`) instead of :keyword:`with` (resp.
|
||
:keyword:`async with`).
|
||
(Contributed by Bénédikt Tran in :gh:`128398`.)
|
||
|
||
|
||
.. _whatsnew314-pep765:
|
||
|
||
PEP 765: Disallow return/break/continue that exit a finally block
|
||
-----------------------------------------------------------------
|
||
|
||
The compiler emits a :exc:`SyntaxWarning` when a :keyword:`return`, :keyword:`break` or
|
||
:keyword:`continue` statements appears where it exits a :keyword:`finally` block.
|
||
This change is specified in :pep:`765`.
|
||
|
||
|
||
New modules
|
||
===========
|
||
|
||
* :mod:`annotationlib`: For introspecting :term:`annotations <annotation>`.
|
||
See :pep:`749` for more details.
|
||
(Contributed by Jelle Zijlstra in :gh:`119180`.)
|
||
|
||
|
||
Improved modules
|
||
================
|
||
|
||
argparse
|
||
--------
|
||
|
||
* The default value of the :ref:`program name <prog>` for
|
||
:class:`argparse.ArgumentParser` now reflects the way the Python
|
||
interpreter was instructed to find the ``__main__`` module code.
|
||
(Contributed by Serhiy Storchaka and Alyssa Coghlan in :gh:`66436`.)
|
||
|
||
* Introduced the optional *suggest_on_error* parameter to
|
||
:class:`argparse.ArgumentParser`, enabling suggestions for argument choices
|
||
and subparser names if mistyped by the user.
|
||
(Contributed by Savannah Ostrowski in :gh:`124456`.)
|
||
|
||
ast
|
||
---
|
||
|
||
* Add :func:`ast.compare` for comparing two ASTs.
|
||
(Contributed by Batuhan Taskaya and Jeremy Hylton in :gh:`60191`.)
|
||
|
||
* Add support for :func:`copy.replace` for AST nodes.
|
||
(Contributed by Bénédikt Tran in :gh:`121141`.)
|
||
|
||
* Docstrings are now removed from an optimized AST in optimization level 2.
|
||
(Contributed by Irit Katriel in :gh:`123958`.)
|
||
|
||
* The ``repr()`` output for AST nodes now includes more information.
|
||
(Contributed by Tomas R in :gh:`116022`.)
|
||
|
||
* :func:`ast.parse`, when called with an AST as input, now always verifies
|
||
that the root node type is appropriate.
|
||
(Contributed by Irit Katriel in :gh:`130139`.)
|
||
|
||
bdb
|
||
---
|
||
|
||
* The :mod:`bdb` module now supports the :mod:`sys.monitoring` backend.
|
||
(Contributed by Tian Gao in :gh:`124533`.)
|
||
|
||
calendar
|
||
--------
|
||
|
||
* By default, today's date is highlighted in color in :mod:`calendar`'s
|
||
:ref:`command-line <calendar-cli>` text output.
|
||
This can be controlled via the :envvar:`PYTHON_COLORS` environment
|
||
variable as well as the canonical |NO_COLOR|_
|
||
and |FORCE_COLOR|_ environment variables.
|
||
See also :ref:`using-on-controlling-color`.
|
||
(Contributed by Hugo van Kemenade in :gh:`128317`.)
|
||
|
||
|
||
concurrent.futures
|
||
------------------
|
||
|
||
* Add :class:`~concurrent.futures.InterpreterPoolExecutor`,
|
||
which exposes "subinterpreters (multiple Python interpreters in the
|
||
same process) to Python code. This is separate from the proposed API
|
||
in :pep:`734`.
|
||
(Contributed by Eric Snow in :gh:`124548`.)
|
||
|
||
.. _whatsnew314-concurrent-futures-start-method:
|
||
|
||
* The default :class:`~concurrent.futures.ProcessPoolExecutor`
|
||
:ref:`start method <multiprocessing-start-methods>` changed
|
||
from :ref:`fork <multiprocessing-start-method-fork>` to :ref:`forkserver
|
||
<multiprocessing-start-method-forkserver>` on platforms other than macOS and
|
||
Windows where it was already :ref:`spawn <multiprocessing-start-method-spawn>`.
|
||
|
||
If the threading incompatible *fork* method is required, you must explicitly
|
||
request it by supplying a multiprocessing context *mp_context* to
|
||
:class:`~concurrent.futures.ProcessPoolExecutor`.
|
||
|
||
See :ref:`forkserver restrictions <multiprocessing-programming-forkserver>`
|
||
for information and differences with the *fork* method and how this change
|
||
may affect existing code with mutable global shared variables and/or shared
|
||
objects that can not be automatically :mod:`pickled <pickle>`.
|
||
|
||
(Contributed by Gregory P. Smith in :gh:`84559`.)
|
||
|
||
* 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`.)
|
||
|
||
* 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.
|
||
(Contributed by Enzo Bonnal and Josh Rosenberg in :gh:`74028`.)
|
||
|
||
|
||
contextvars
|
||
-----------
|
||
|
||
* Support context manager protocol by :class:`contextvars.Token`.
|
||
(Contributed by Andrew Svetlov in :gh:`129889`.)
|
||
|
||
|
||
ctypes
|
||
------
|
||
|
||
* The layout of :ref:`bit fields <ctypes-bit-fields-in-structures-unions>`
|
||
in :class:`~ctypes.Structure` and :class:`~ctypes.Union`
|
||
now matches platform defaults (GCC/Clang or MSVC) more closely.
|
||
In particular, fields no longer overlap.
|
||
(Contributed by Matthias Görgens in :gh:`97702`.)
|
||
|
||
* The :attr:`.Structure._layout_` class attribute can now be set
|
||
to help match a non-default ABI.
|
||
(Contributed by Petr Viktorin in :gh:`97702`.)
|
||
|
||
* The class of :class:`~ctypes.Structure`/:class:`~ctypes.Union`
|
||
field descriptors is now available as :class:`~ctypes.CField`,
|
||
and has new attributes to aid debugging and introspection.
|
||
(Contributed by Petr Viktorin in :gh:`128715`.)
|
||
|
||
* On Windows, the :exc:`~ctypes.COMError` exception is now public.
|
||
(Contributed by Jun Komoda in :gh:`126686`.)
|
||
|
||
* On Windows, the :func:`~ctypes.CopyComPointer` function is now public.
|
||
(Contributed by Jun Komoda in :gh:`127275`.)
|
||
|
||
* :func:`ctypes.memoryview_at` now exists to create a
|
||
:class:`memoryview` object that refers to the supplied pointer and
|
||
length. This works like :func:`ctypes.string_at` except it avoids a
|
||
buffer copy, and is typically useful when implementing pure Python
|
||
callback functions that are passed dynamically-sized buffers.
|
||
(Contributed by Rian Hunter in :gh:`112018`.)
|
||
|
||
* Complex types, :class:`~ctypes.c_float_complex`,
|
||
:class:`~ctypes.c_double_complex` and :class:`~ctypes.c_longdouble_complex`,
|
||
are now available if both the compiler and the ``libffi`` library support
|
||
complex C types.
|
||
(Contributed by Sergey B Kirpichev in :gh:`61103`).
|
||
|
||
* Add :func:`ctypes.util.dllist` for listing the shared libraries
|
||
loaded by the current process.
|
||
(Contributed by Brian Ward in :gh:`119349`.)
|
||
|
||
* Move :func:`ctypes.POINTER` types cache from a global internal cache
|
||
(``_pointer_type_cache``) to the :attr:`ctypes._CData.__pointer_type__`
|
||
attribute of the corresponding :mod:`ctypes` types.
|
||
This will stop the cache from growing without limits in some situations.
|
||
(Contributed by Sergey Miryanov in :gh:`100926`).
|
||
|
||
* The :class:`ctypes.py_object` type now supports subscription,
|
||
making it a :term:`generic type`.
|
||
(Contributed by Brian Schubert in :gh:`132168`.)
|
||
|
||
datetime
|
||
--------
|
||
|
||
* Add :meth:`datetime.time.strptime` and :meth:`datetime.date.strptime`.
|
||
(Contributed by Wannes Boeykens in :gh:`41431`.)
|
||
|
||
decimal
|
||
-------
|
||
|
||
* Add alternative :class:`~decimal.Decimal` constructor
|
||
:meth:`Decimal.from_number() <decimal.Decimal.from_number>`.
|
||
(Contributed by Serhiy Storchaka in :gh:`121798`.)
|
||
|
||
* Expose :func:`decimal.IEEEContext` to support creation of contexts
|
||
corresponding to the IEEE 754 (2008) decimal interchange formats.
|
||
(Contributed by Sergey B Kirpichev in :gh:`53032`.)
|
||
|
||
difflib
|
||
-------
|
||
|
||
* Comparison pages with highlighted changes generated by the
|
||
:class:`difflib.HtmlDiff` class now support dark mode.
|
||
(Contributed by Jiahao Li in :gh:`129939`.)
|
||
|
||
dis
|
||
---
|
||
|
||
* Add support for rendering full source location information of
|
||
:class:`instructions <dis.Instruction>`, rather than only the line number.
|
||
This feature is added to the following interfaces via the *show_positions*
|
||
keyword argument:
|
||
|
||
- :class:`dis.Bytecode`
|
||
- :func:`dis.dis`
|
||
- :func:`dis.distb`
|
||
- :func:`dis.disassemble`
|
||
|
||
This feature is also exposed via :option:`dis --show-positions`.
|
||
(Contributed by Bénédikt Tran in :gh:`123165`.)
|
||
|
||
* Add the :option:`dis --specialized` command-line option to
|
||
show specialized bytecode.
|
||
(Contributed by Bénédikt Tran in :gh:`127413`.)
|
||
|
||
|
||
errno
|
||
-----
|
||
|
||
* Add :data:`errno.EHWPOISON` error code.
|
||
(Contributed by James Roy in :gh:`126585`.)
|
||
|
||
|
||
faulthandler
|
||
------------
|
||
|
||
* Add support for printing the C stack trace on systems that
|
||
:ref:`support it <c-stack-compatibility>` via :func:`faulthandler.dump_c_stack`
|
||
or via the *c_stack* argument in :func:`faulthandler.enable`.
|
||
(Contributed by Peter Bierma in :gh:`127604`.)
|
||
|
||
|
||
fnmatch
|
||
-------
|
||
|
||
* Added :func:`fnmatch.filterfalse` for excluding names matching a pattern.
|
||
(Contributed by Bénédikt Tran in :gh:`74598`.)
|
||
|
||
|
||
fractions
|
||
---------
|
||
|
||
* Add support for converting any objects that have the
|
||
:meth:`!as_integer_ratio` method to a :class:`~fractions.Fraction`.
|
||
(Contributed by Serhiy Storchaka in :gh:`82017`.)
|
||
|
||
* Add alternative :class:`~fractions.Fraction` constructor
|
||
:meth:`Fraction.from_number() <fractions.Fraction.from_number>`.
|
||
(Contributed by Serhiy Storchaka in :gh:`121797`.)
|
||
|
||
|
||
functools
|
||
---------
|
||
|
||
* Add support to :func:`functools.partial` and
|
||
:func:`functools.partialmethod` for :data:`functools.Placeholder` sentinels
|
||
to reserve a place for positional arguments.
|
||
(Contributed by Dominykas Grigonis in :gh:`119127`.)
|
||
|
||
* Allow the *initial* parameter of :func:`functools.reduce` to be passed
|
||
as a keyword argument.
|
||
(Contributed by Sayandip Dutta in :gh:`125916`.)
|
||
|
||
|
||
getopt
|
||
------
|
||
|
||
* Add support for options with optional arguments.
|
||
(Contributed by Serhiy Storchaka in :gh:`126374`.)
|
||
|
||
* Add support for returning intermixed options and non-option arguments in order.
|
||
(Contributed by Serhiy Storchaka in :gh:`126390`.)
|
||
|
||
|
||
graphlib
|
||
--------
|
||
|
||
* Allow :meth:`graphlib.TopologicalSorter.prepare` to be called more than once
|
||
as long as sorting has not started.
|
||
(Contributed by Daniel Pope in :gh:`130914`)
|
||
|
||
|
||
hmac
|
||
----
|
||
|
||
* Add a built-in implementation for HMAC (:rfc:`2104`) using formally verified
|
||
code from the `HACL* <https://github.com/hacl-star/hacl-star/>`__ project.
|
||
(Contributed by Bénédikt Tran in :gh:`99108`.)
|
||
|
||
|
||
http
|
||
----
|
||
|
||
* Directory lists and error pages generated by the :mod:`http.server`
|
||
module allow the browser to apply its default dark mode.
|
||
(Contributed by Yorik Hansen in :gh:`123430`.)
|
||
|
||
* The :mod:`http.server` module now supports serving over HTTPS using the
|
||
:class:`http.server.HTTPSServer` class. This functionality is exposed by
|
||
the command-line interface (``python -m http.server``) through the following
|
||
options:
|
||
|
||
* ``--tls-cert <path>``: Path to the TLS certificate file.
|
||
* ``--tls-key <path>``: Optional path to the private key file.
|
||
* ``--tls-password-file <path>``: Optional path to the password file for the private key.
|
||
|
||
(Contributed by Semyon Moroz in :gh:`85162`.)
|
||
|
||
|
||
imaplib
|
||
-------
|
||
|
||
* Add :meth:`IMAP4.idle() <imaplib.IMAP4.idle>`, implementing the IMAP4
|
||
``IDLE`` command as defined in :rfc:`2177`.
|
||
(Contributed by Forest in :gh:`55454`.)
|
||
|
||
|
||
inspect
|
||
-------
|
||
|
||
* :func:`inspect.signature` takes a new argument *annotation_format* to control
|
||
the :class:`annotationlib.Format` used for representing annotations.
|
||
(Contributed by Jelle Zijlstra in :gh:`101552`.)
|
||
|
||
* :meth:`inspect.Signature.format` takes a new argument *unquote_annotations*.
|
||
If true, string :term:`annotations <annotation>` are displayed without surrounding quotes.
|
||
(Contributed by Jelle Zijlstra in :gh:`101552`.)
|
||
|
||
* Add function :func:`inspect.ispackage` to determine whether an object is a
|
||
:term:`package` or not.
|
||
(Contributed by Zhikang Yan in :gh:`125634`.)
|
||
|
||
|
||
io
|
||
--
|
||
|
||
* Reading text from a non-blocking stream with ``read`` may now raise a
|
||
:exc:`BlockingIOError` if the operation cannot immediately return bytes.
|
||
(Contributed by Giovanni Siragusa in :gh:`109523`.)
|
||
|
||
* Add protocols :class:`io.Reader` and :class:`io.Writer` as a simpler
|
||
alternatives to the pseudo-protocols :class:`typing.IO`,
|
||
:class:`typing.TextIO`, and :class:`typing.BinaryIO`.
|
||
(Contributed by Sebastian Rittau in :gh:`127648`.)
|
||
|
||
|
||
json
|
||
----
|
||
|
||
* Add notes for JSON serialization errors that allow to identify the source
|
||
of the error.
|
||
(Contributed by Serhiy Storchaka in :gh:`122163`.)
|
||
|
||
* Enable the :mod:`json` module to work as a script using the :option:`-m`
|
||
switch: :program:`python -m json`.
|
||
See the :ref:`JSON command-line interface <json-commandline>` documentation.
|
||
(Contributed by Trey Hunner in :gh:`122873`.)
|
||
|
||
* By default, the output of the :ref:`JSON command-line interface <json-commandline>`
|
||
is highlighted in color. This can be controlled via the
|
||
:envvar:`PYTHON_COLORS` environment variable as well as the canonical
|
||
|NO_COLOR|_ and |FORCE_COLOR|_ environment variables. See also
|
||
:ref:`using-on-controlling-color`.
|
||
(Contributed by Tomas Roun in :gh:`131952`.)
|
||
|
||
linecache
|
||
---------
|
||
|
||
* :func:`linecache.getline` can retrieve source code for frozen modules.
|
||
(Contributed by Tian Gao in :gh:`131638`.)
|
||
|
||
|
||
logging.handlers
|
||
----------------
|
||
|
||
* :class:`logging.handlers.QueueListener` now implements the context
|
||
manager protocol, allowing it to be used in a :keyword:`with` statement.
|
||
(Contributed by Charles Machalow in :gh:`132106`.)
|
||
|
||
* :meth:`QueueListener.start <logging.handlers.QueueListener.start>` now
|
||
raises a :exc:`RuntimeError` if the listener is already started.
|
||
(Contributed by Charles Machalow in :gh:`132106`.)
|
||
|
||
|
||
math
|
||
----
|
||
|
||
* Added more detailed error messages for domain errors in the module.
|
||
(Contributed by by Charlie Zhao and Sergey B Kirpichev in :gh:`101410`.)
|
||
|
||
|
||
mimetypes
|
||
---------
|
||
|
||
* 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.
|
||
(Contributed by Oleg Iarygin and Hugo van Kemenade in :gh:`93096`.)
|
||
|
||
* Add MS and :rfc:`8081` MIME types for fonts:
|
||
|
||
* Embedded OpenType: ``application/vnd.ms-fontobject``
|
||
* OpenType Layout (OTF) ``font/otf``
|
||
* TrueType: ``font/ttf``
|
||
* WOFF 1.0 ``font/woff``
|
||
* WOFF 2.0 ``font/woff2``
|
||
|
||
(Contributed by Sahil Prajapati and Hugo van Kemenade in :gh:`84852`.)
|
||
|
||
* Add :rfc:`9559` MIME types for Matroska audiovisual data container
|
||
structures, containing:
|
||
|
||
* audio with no video: ``audio/matroska`` (``.mka``)
|
||
* video: ``video/matroska`` (``.mkv``)
|
||
* stereoscopic video: ``video/matroska-3d`` (``.mk3d``)
|
||
|
||
(Contributed by Hugo van Kemenade in :gh:`89416`.)
|
||
|
||
* Add MIME types for images with RFCs:
|
||
|
||
* :rfc:`1494`: CCITT Group 3 (``.g3``)
|
||
* :rfc:`3362`: Real-time Facsimile, T.38 (``.t38``)
|
||
* :rfc:`3745`: JPEG 2000 (``.jp2``), extension (``.jpx``) and compound (``.jpm``)
|
||
* :rfc:`3950`: Tag Image File Format Fax eXtended, TIFF-FX (``.tfx``)
|
||
* :rfc:`4047`: Flexible Image Transport System (``.fits``)
|
||
* :rfc:`7903`: Enhanced Metafile (``.emf``) and Windows Metafile (``.wmf``)
|
||
|
||
(Contributed by Hugo van Kemenade in :gh:`85957`.)
|
||
|
||
* More MIME type changes:
|
||
|
||
* :rfc:`2361`: Change type for ``.avi`` to ``video/vnd.avi``
|
||
and for ``.wav`` to ``audio/vnd.wave``
|
||
* :rfc:`4337`: Add MPEG-4 ``audio/mp4`` (``.m4a``)
|
||
* :rfc:`5334`: Add Ogg media (``.oga``, ``.ogg`` and ``.ogx``)
|
||
* :rfc:`6713`: Add gzip ``application/gzip`` (``.gz``)
|
||
* :rfc:`9639`: Add FLAC ``audio/flac`` (``.flac``)
|
||
* Add 7z ``application/x-7z-compressed`` (``.7z``)
|
||
* Add Android Package ``application/vnd.android.package-archive`` (``.apk``)
|
||
when not strict
|
||
* Add deb ``application/x-debian-package`` (``.deb``)
|
||
* Add glTF binary ``model/gltf-binary`` (``.glb``)
|
||
* Add glTF JSON/ASCII ``model/gltf+json`` (``.gltf``)
|
||
* Add M4V ``video/x-m4v`` (``.m4v``)
|
||
* Add PHP ``application/x-httpd-php`` (``.php``)
|
||
* Add RAR ``application/vnd.rar`` (``.rar``)
|
||
* Add RPM ``application/x-rpm`` (``.rpm``)
|
||
* Add STL ``model/stl`` (``.stl``)
|
||
* Add Windows Media Video ``video/x-ms-wmv`` (``.wmv``)
|
||
* De facto: Add WebM ``audio/webm`` (``.weba``)
|
||
* `ECMA-376
|
||
<https://ecma-international.org/publications-and-standards/standards/ecma-376/>`__:
|
||
Add ``.docx``, ``.pptx`` and ``.xlsx`` types
|
||
* `OASIS
|
||
<https://docs.oasis-open.org/office/v1.2/cs01/OpenDocument-v1.2-cs01-part1.html#Appendix_C>`__:
|
||
Add OpenDocument ``.odg``, ``.odp``, ``.ods`` and ``.odt`` types
|
||
* `W3C <https://www.w3.org/TR/epub-33/#app-media-type>`__:
|
||
Add EPUB ``application/epub+zip`` (``.epub``)
|
||
|
||
(Contributed by Hugo van Kemenade in :gh:`129965`.)
|
||
|
||
* Add :rfc:`9512` ``application/yaml`` MIME type for YAML files (``.yaml``
|
||
and ``.yml``). (Contributed by Sasha "Nelie" Chernykh and Hugo van Kemenade
|
||
in :gh:`132056`.)
|
||
|
||
|
||
multiprocessing
|
||
---------------
|
||
|
||
.. _whatsnew314-multiprocessing-start-method:
|
||
|
||
* The default :ref:`start method <multiprocessing-start-methods>` changed
|
||
from :ref:`fork <multiprocessing-start-method-fork>` to :ref:`forkserver
|
||
<multiprocessing-start-method-forkserver>` on platforms other than macOS and
|
||
Windows where it was already :ref:`spawn <multiprocessing-start-method-spawn>`.
|
||
|
||
If the threading incompatible *fork* method is required, you must explicitly
|
||
request it via a context from :func:`multiprocessing.get_context` (preferred)
|
||
or change the default via :func:`multiprocessing.set_start_method`.
|
||
|
||
See :ref:`forkserver restrictions <multiprocessing-programming-forkserver>`
|
||
for information and differences with the *fork* method and how this change
|
||
may affect existing code with mutable global shared variables and/or shared
|
||
objects that can not be automatically :mod:`pickled <pickle>`.
|
||
|
||
(Contributed by Gregory P. Smith in :gh:`84559`.)
|
||
|
||
* :mod:`multiprocessing`'s ``"forkserver"`` start method now authenticates
|
||
its control socket to avoid solely relying on filesystem permissions
|
||
to restrict what other processes could cause the forkserver to spawn workers
|
||
and run code.
|
||
(Contributed by Gregory P. Smith for :gh:`97514`.)
|
||
|
||
* The :ref:`multiprocessing proxy objects <multiprocessing-proxy_objects>`
|
||
for *list* and *dict* types gain previously overlooked missing methods:
|
||
|
||
* :meth:`!clear` and :meth:`!copy` for proxies of :class:`list`.
|
||
* :meth:`~dict.fromkeys`, ``reversed(d)``, ``d | {}``, ``{} | d``,
|
||
``d |= {'b': 2}`` for proxies of :class:`dict`.
|
||
|
||
(Contributed by Roy Hyunjin Han for :gh:`103134`.)
|
||
|
||
* Add support for shared :class:`set` objects via
|
||
:meth:`SyncManager.set() <multiprocessing.managers.SyncManager.set>`.
|
||
The :func:`set` in :func:`multiprocessing.Manager` method is now available.
|
||
(Contributed by Mingyu Park in :gh:`129949`.)
|
||
|
||
* Add :func:`multiprocessing.Process.interrupt` which terminates the child
|
||
process by sending :py:const:`~signal.SIGINT`. This enables "finally" clauses
|
||
and printing stack trace for the terminated process.
|
||
(Contributed by Artem Pulkin in :gh:`131913`.)
|
||
|
||
operator
|
||
--------
|
||
|
||
* Two new functions :func:`operator.is_none` and :func:`operator.is_not_none`
|
||
have been added, such that ``operator.is_none(obj)`` is equivalent
|
||
to ``obj is None`` and ``operator.is_not_none(obj)`` is equivalent
|
||
to ``obj is not None``.
|
||
(Contributed by Raymond Hettinger and Nico Mexis in :gh:`115808`.)
|
||
|
||
|
||
os
|
||
--
|
||
|
||
* Add the :func:`os.reload_environ` function to update :data:`os.environ` and
|
||
:data:`os.environb` with changes to the environment made by
|
||
:func:`os.putenv`, by :func:`os.unsetenv`, or made outside Python in the
|
||
same process.
|
||
(Contributed by Victor Stinner in :gh:`120057`.)
|
||
|
||
* Add the :data:`~os.SCHED_DEADLINE` and :data:`~os.SCHED_NORMAL` constants
|
||
to the :mod:`os` module.
|
||
(Contributed by James Roy in :gh:`127688`.)
|
||
|
||
* Add the :func:`os.readinto` function to read into a
|
||
:ref:`buffer object <bufferobjects>` from a file descriptor.
|
||
(Contributed by Cody Maloney in :gh:`129205`.)
|
||
|
||
|
||
pathlib
|
||
-------
|
||
|
||
* Add methods to :class:`pathlib.Path` to recursively copy or move files and
|
||
directories:
|
||
|
||
* :meth:`~pathlib.Path.copy` copies a file or directory tree to a destination.
|
||
* :meth:`~pathlib.Path.copy_into` copies *into* a destination directory.
|
||
* :meth:`~pathlib.Path.move` moves a file or directory tree to a destination.
|
||
* :meth:`~pathlib.Path.move_into` moves *into* a destination directory.
|
||
|
||
(Contributed by Barney Gale in :gh:`73991`.)
|
||
|
||
* Add :attr:`pathlib.Path.info` attribute, which stores an object
|
||
implementing the :class:`pathlib.types.PathInfo` protocol (also new). The
|
||
object supports querying the file type and internally caching
|
||
:func:`~os.stat` results. Path objects generated by
|
||
:meth:`~pathlib.Path.iterdir` are initialized with file type information
|
||
gleaned from scanning the parent directory.
|
||
(Contributed by Barney Gale in :gh:`125413`.)
|
||
|
||
|
||
pdb
|
||
---
|
||
|
||
* Hardcoded breakpoints (:func:`breakpoint` and :func:`pdb.set_trace`) now
|
||
reuse the most recent :class:`~pdb.Pdb` instance that calls
|
||
:meth:`~pdb.Pdb.set_trace`, instead of creating a new one each time.
|
||
As a result, all the instance specific data like :pdbcmd:`display` and
|
||
:pdbcmd:`commands` are preserved across hardcoded breakpoints.
|
||
(Contributed by Tian Gao in :gh:`121450`.)
|
||
|
||
* Add a new argument *mode* to :class:`pdb.Pdb`. Disable the ``restart``
|
||
command when :mod:`pdb` is in ``inline`` mode.
|
||
(Contributed by Tian Gao in :gh:`123757`.)
|
||
|
||
* A confirmation prompt will be shown when the user tries to quit :mod:`pdb`
|
||
in ``inline`` mode. ``y``, ``Y``, ``<Enter>`` or ``EOF`` will confirm
|
||
the quit and call :func:`sys.exit`, instead of raising :exc:`bdb.BdbQuit`.
|
||
(Contributed by Tian Gao in :gh:`124704`.)
|
||
|
||
* Inline breakpoints like :func:`breakpoint` or :func:`pdb.set_trace` will
|
||
always stop the program at calling frame, ignoring the ``skip`` pattern
|
||
(if any).
|
||
(Contributed by Tian Gao in :gh:`130493`.)
|
||
|
||
* ``<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.
|
||
(Contributed by Tian Gao in :gh:`130471`.)
|
||
|
||
* ``$_asynctask`` is added to access the current asyncio task if applicable.
|
||
(Contributed by Tian Gao in :gh:`124367`.)
|
||
|
||
* :mod:`pdb` now supports two backends: :func:`sys.settrace` and
|
||
:mod:`sys.monitoring`. Using :mod:`pdb` CLI or :func:`breakpoint` will
|
||
always use the :mod:`sys.monitoring` backend. Explicitly instantiating
|
||
:class:`pdb.Pdb` and its derived classes will use the :func:`sys.settrace`
|
||
backend by default, which is configurable.
|
||
(Contributed by Tian Gao in :gh:`124533`.)
|
||
|
||
* :func:`pdb.set_trace_async` is added to support debugging asyncio
|
||
coroutines. :keyword:`await` statements are supported with this
|
||
function.
|
||
(Contributed by Tian Gao in :gh:`132576`.)
|
||
|
||
|
||
pickle
|
||
------
|
||
|
||
* Set the default protocol version on the :mod:`pickle` module to 5.
|
||
For more details, see :ref:`pickle protocols <pickle-protocols>`.
|
||
|
||
* Add notes for pickle serialization errors that allow to identify the source
|
||
of the error.
|
||
(Contributed by Serhiy Storchaka in :gh:`122213`.)
|
||
|
||
|
||
platform
|
||
--------
|
||
|
||
* Add :func:`platform.invalidate_caches` to invalidate the cached results.
|
||
(Contributed by Bénédikt Tran in :gh:`122549`.)
|
||
|
||
|
||
pydoc
|
||
-----
|
||
|
||
* :term:`Annotations <annotation>` in help output are now usually
|
||
displayed in a format closer to that in the original source.
|
||
(Contributed by Jelle Zijlstra in :gh:`101552`.)
|
||
|
||
|
||
socket
|
||
------
|
||
|
||
* Improve and fix support for Bluetooth sockets.
|
||
|
||
* Fix support of Bluetooth sockets on NetBSD and DragonFly BSD.
|
||
(Contributed by Serhiy Storchaka in :gh:`132429`.)
|
||
* Fix support for :const:`~socket.BTPROTO_HCI` on FreeBSD.
|
||
(Contributed by Victor Stinner in :gh:`111178`.)
|
||
* Add support for :const:`~socket.BTPROTO_SCO` on FreeBSD.
|
||
(Contributed by Serhiy Storchaka in :gh:`85302`.)
|
||
* Add support for *cid* and *bdaddr_type* in the address for
|
||
:const:`~socket.BTPROTO_L2CAP` on FreeBSD.
|
||
(Contributed by Serhiy Storchaka in :gh:`132429`.)
|
||
* Add support for *channel* in the address for
|
||
:const:`~socket.BTPROTO_HCI` on Linux.
|
||
(Contributed by Serhiy Storchaka in :gh:`70145`.)
|
||
* Accept an integer as the address for
|
||
:const:`~socket.BTPROTO_HCI` on Linux
|
||
(Contributed by Serhiy Storchaka in :gh:`132099`.)
|
||
* Return *cid* in :meth:`~socket.socket.getsockname` for
|
||
:const:`~socket.BTPROTO_L2CAP`.
|
||
(Contributed by Serhiy Storchaka in :gh:`132429`.)
|
||
* Add many new constants.
|
||
(Contributed by Serhiy Storchaka in :gh:`132734`.)
|
||
|
||
ssl
|
||
---
|
||
|
||
* Indicate through :data:`ssl.HAS_PHA` whether the :mod:`ssl` module supports
|
||
TLSv1.3 post-handshake client authentication (PHA).
|
||
(Contributed by Will Childs-Klein in :gh:`128036`.)
|
||
|
||
|
||
struct
|
||
------
|
||
|
||
* Support the :c:expr:`float complex` and :c:expr:`double complex` C types in
|
||
the :mod:`struct` module (formatting characters ``'F'`` and ``'D'``
|
||
respectively).
|
||
(Contributed by Sergey B Kirpichev in :gh:`121249`.)
|
||
|
||
|
||
symtable
|
||
--------
|
||
|
||
* Expose the following :class:`symtable.Symbol` methods:
|
||
|
||
* :meth:`~symtable.Symbol.is_comp_cell`
|
||
* :meth:`~symtable.Symbol.is_comp_iter`
|
||
* :meth:`~symtable.Symbol.is_free_class`
|
||
|
||
(Contributed by Bénédikt Tran in :gh:`120029`.)
|
||
|
||
|
||
sys
|
||
---
|
||
|
||
* The previously undocumented special function :func:`sys.getobjects`,
|
||
which only exists in specialized builds of Python, may now return objects
|
||
from other interpreters than the one it's called in.
|
||
|
||
* Add :func:`sys._is_immortal` for determining if an object is :term:`immortal`.
|
||
(Contributed by Peter Bierma in :gh:`128509`.)
|
||
|
||
* On FreeBSD, :data:`sys.platform` doesn't contain the major version anymore.
|
||
It is always ``'freebsd'``, instead of ``'freebsd13'`` or ``'freebsd14'``.
|
||
|
||
* Raise :exc:`DeprecationWarning` for :func:`sys._clear_type_cache`. This
|
||
function was deprecated in Python 3.13 but it didn't raise a runtime warning.
|
||
|
||
|
||
sys.monitoring
|
||
--------------
|
||
|
||
* Two new events are added: :monitoring-event:`BRANCH_LEFT` and
|
||
:monitoring-event:`BRANCH_RIGHT`. The ``BRANCH`` event is deprecated.
|
||
|
||
|
||
sysconfig
|
||
---------
|
||
|
||
* Add ``ABIFLAGS`` key to :func:`sysconfig.get_config_vars` on Windows.
|
||
(Contributed by Xuehai Pan in :gh:`131799`.)
|
||
|
||
|
||
threading
|
||
---------
|
||
|
||
* :meth:`threading.Thread.start` now sets the operating system thread name
|
||
to :attr:`threading.Thread.name`.
|
||
(Contributed by Victor Stinner in :gh:`59705`.)
|
||
|
||
|
||
tkinter
|
||
-------
|
||
|
||
* Make tkinter widget methods :meth:`!after` and :meth:`!after_idle` accept
|
||
arguments passed by keyword.
|
||
(Contributed by Zhikang Yan in :gh:`126899`.)
|
||
|
||
* Add ability to specify name for :class:`!tkinter.OptionMenu` and
|
||
:class:`!tkinter.ttk.OptionMenu`.
|
||
(Contributed by Zhikang Yan in :gh:`130482`.)
|
||
|
||
turtle
|
||
------
|
||
|
||
* Add context managers for :func:`turtle.fill`, :func:`turtle.poly`
|
||
and :func:`turtle.no_animation`.
|
||
(Contributed by Marie Roald and Yngve Mardal Moe in :gh:`126350`.)
|
||
|
||
|
||
types
|
||
-----
|
||
|
||
* :class:`types.UnionType` is now an alias for :class:`typing.Union`.
|
||
See :ref:`below <whatsnew314-typing-union>` for more details.
|
||
(Contributed by Jelle Zijlstra in :gh:`105499`.)
|
||
|
||
|
||
typing
|
||
------
|
||
|
||
.. _whatsnew314-typing-union:
|
||
|
||
* :class:`types.UnionType` and :class:`typing.Union` are now aliases for each other,
|
||
meaning that both old-style unions (created with ``Union[int, str]``) and new-style
|
||
unions (``int | str``) now create instances of the same runtime type. This unifies
|
||
the behavior between the two syntaxes, but leads to some differences in behavior that
|
||
may affect users who introspect types at runtime:
|
||
|
||
- Both syntaxes for creating a union now produce the same string representation in
|
||
``repr()``. For example, ``repr(Union[int, str])``
|
||
is now ``"int | str"`` instead of ``"typing.Union[int, str]"``.
|
||
- Unions created using the old syntax are no longer cached. Previously, running
|
||
``Union[int, str]`` multiple times would return the same object
|
||
(``Union[int, str] is Union[int, str]`` would be ``True``), but now it will
|
||
return two different objects. Users should use ``==`` to compare unions for equality, not
|
||
``is``. New-style unions have never been cached this way.
|
||
This change could increase memory usage for some programs that use a large number of
|
||
unions created by subscripting ``typing.Union``. However, several factors offset this cost:
|
||
unions used in annotations are no longer evaluated by default in Python 3.14
|
||
because of :pep:`649`; an instance of :class:`types.UnionType` is
|
||
itself much smaller than the object returned by ``Union[]`` was on prior Python
|
||
versions; and removing the cache also saves some space. It is therefore
|
||
unlikely that this change will cause a significant increase in memory usage for most
|
||
users.
|
||
- Previously, old-style unions were implemented using the private class
|
||
``typing._UnionGenericAlias``. This class is no longer needed for the implementation,
|
||
but it has been retained for backward compatibility, with removal scheduled for Python
|
||
3.17. Users should use documented introspection helpers like :func:`typing.get_origin`
|
||
and :func:`typing.get_args` instead of relying on private implementation details.
|
||
- It is now possible to use :class:`typing.Union` itself in :func:`isinstance` checks.
|
||
For example, ``isinstance(int | str, typing.Union)`` will return ``True``; previously
|
||
this raised :exc:`TypeError`.
|
||
- The ``__args__`` attribute of :class:`typing.Union` objects is no longer writable.
|
||
- It is no longer possible to set any attributes on :class:`typing.Union` objects.
|
||
This only ever worked for dunder attributes on previous versions, was never
|
||
documented to work, and was subtly broken in many cases.
|
||
|
||
(Contributed by Jelle Zijlstra in :gh:`105499`.)
|
||
|
||
|
||
unicodedata
|
||
-----------
|
||
|
||
* The Unicode database has been updated to Unicode 16.0.0.
|
||
|
||
|
||
unittest
|
||
--------
|
||
|
||
* :mod:`unittest` output is now colored by default.
|
||
This can be controlled via the :envvar:`PYTHON_COLORS` environment
|
||
variable as well as the canonical |NO_COLOR|_
|
||
and |FORCE_COLOR|_ environment variables.
|
||
See also :ref:`using-on-controlling-color`.
|
||
(Contributed by Hugo van Kemenade in :gh:`127221`.)
|
||
|
||
* unittest discovery supports :term:`namespace package` as start
|
||
directory again. It was removed in Python 3.11.
|
||
(Contributed by Jacob Walls in :gh:`80958`.)
|
||
|
||
* A number of new methods were added in the :class:`~unittest.TestCase` class
|
||
that provide more specialized tests.
|
||
|
||
- :meth:`~unittest.TestCase.assertHasAttr` and
|
||
:meth:`~unittest.TestCase.assertNotHasAttr` check whether the object
|
||
has a particular attribute.
|
||
- :meth:`~unittest.TestCase.assertIsSubclass` and
|
||
:meth:`~unittest.TestCase.assertNotIsSubclass` check whether the object
|
||
is a subclass of a particular class, or of one of a tuple of classes.
|
||
- :meth:`~unittest.TestCase.assertStartsWith`,
|
||
:meth:`~unittest.TestCase.assertNotStartsWith`,
|
||
:meth:`~unittest.TestCase.assertEndsWith` and
|
||
:meth:`~unittest.TestCase.assertNotEndsWith` check whether the Unicode
|
||
or byte string starts or ends with particular string(s).
|
||
|
||
(Contributed by Serhiy Storchaka in :gh:`71339`.)
|
||
|
||
|
||
urllib
|
||
------
|
||
|
||
* Upgrade HTTP digest authentication algorithm for :mod:`urllib.request` by
|
||
supporting SHA-256 digest authentication as specified in :rfc:`7616`.
|
||
(Contributed by Calvin Bui in :gh:`128193`.)
|
||
|
||
* Improve ergonomics and standards compliance when parsing and emitting
|
||
``file:`` URLs.
|
||
|
||
In :func:`urllib.request.url2pathname`:
|
||
|
||
- Accept a complete URL when the new *require_scheme* argument is set to
|
||
true.
|
||
- Discard URL authorities that resolve to a local IP address.
|
||
- Raise :exc:`~urllib.error.URLError` if a URL authority doesn't resolve
|
||
to a local IP address, except on Windows where we return a UNC path.
|
||
|
||
In :func:`urllib.request.pathname2url`:
|
||
|
||
- Return a complete URL when the new *add_scheme* argument is set to true.
|
||
- Include an empty URL authority when a path begins with a slash. For
|
||
example, the path ``/etc/hosts`` is converted to the URL ``///etc/hosts``.
|
||
|
||
On Windows, drive letters are no longer converted to uppercase, and ``:``
|
||
characters not following a drive letter no longer cause an :exc:`OSError`
|
||
exception to be raised.
|
||
|
||
(Contributed by Barney Gale in :gh:`125866`.)
|
||
|
||
|
||
uuid
|
||
----
|
||
|
||
* Add support for UUID versions 6, 7, and 8 via :func:`uuid.uuid6`,
|
||
:func:`uuid.uuid7`, and :func:`uuid.uuid8` respectively, as specified
|
||
in :rfc:`9562`.
|
||
(Contributed by Bénédikt Tran in :gh:`89083`.)
|
||
|
||
* :const:`uuid.NIL` and :const:`uuid.MAX` are now available to represent the
|
||
Nil and Max UUID formats as defined by :rfc:`9562`.
|
||
(Contributed by Nick Pope in :gh:`128427`.)
|
||
|
||
* Allow to generate multiple UUIDs at once via :option:`python -m uuid --count <uuid --count>`.
|
||
(Contributed by Simon Legner in :gh:`131236`.)
|
||
|
||
|
||
webbrowser
|
||
----------
|
||
|
||
* Names in the :envvar:`BROWSER` environment variable can now refer to already
|
||
registered browsers for the :mod:`webbrowser` module, instead of always
|
||
generating a new browser command.
|
||
|
||
This makes it possible to set :envvar:`BROWSER` to the value of one of the
|
||
supported browsers on macOS.
|
||
|
||
|
||
zipinfo
|
||
-------
|
||
|
||
* Added :func:`ZipInfo._for_archive <zipfile.ZipInfo._for_archive>`
|
||
to resolve suitable defaults for a :class:`~zipfile.ZipInfo` object
|
||
as used by :func:`ZipFile.writestr <zipfile.ZipFile.writestr>`.
|
||
(Contributed by Bénédikt Tran in :gh:`123424`.)
|
||
|
||
* :meth:`zipfile.ZipFile.writestr` now respect ``SOURCE_DATE_EPOCH`` that
|
||
distributions can set centrally and have build tools consume this in order
|
||
to produce reproducible output.
|
||
(Contributed by Jiahao Li in :gh:`91279`.)
|
||
|
||
|
||
.. Add improved modules above alphabetically, not here at the end.
|
||
|
||
Optimizations
|
||
=============
|
||
|
||
* The import time for several standard library modules has been improved,
|
||
including :mod:`ast`, :mod:`asyncio`, :mod:`base64`, :mod:`cmd`, :mod:`csv`,
|
||
:mod:`gettext`, :mod:`importlib.util`, :mod:`locale`, :mod:`mimetypes`,
|
||
:mod:`optparse`, :mod:`pickle`, :mod:`pprint`, :mod:`pstats`, :mod:`socket`,
|
||
:mod:`subprocess`, :mod:`threading`, :mod:`tomllib`, and :mod:`zipfile`.
|
||
|
||
(Contributed by Adam Turner, Bénédikt Tran, Chris Markiewicz, Eli Schwartz,
|
||
Hugo van Kemenade, Jelle Zijlstra, and others in :gh:`118761`.)
|
||
|
||
|
||
asyncio
|
||
-------
|
||
|
||
* :mod:`asyncio` now uses double linked list implementation for native tasks
|
||
which speeds up execution by 10% on standard pyperformance benchmarks and
|
||
reduces memory usage.
|
||
(Contributed by Kumar Aditya in :gh:`107803`.)
|
||
|
||
* :mod:`asyncio` has new utility functions for introspecting and printing
|
||
the program's call graph: :func:`asyncio.capture_call_graph` and
|
||
:func:`asyncio.print_call_graph`.
|
||
(Contributed by Yury Selivanov, Pablo Galindo Salgado, and Łukasz Langa
|
||
in :gh:`91048`.)
|
||
|
||
base64
|
||
------
|
||
|
||
* Improve the performance of :func:`base64.b16decode` by up to ten times,
|
||
and reduce the import time of :mod:`base64` by up to six times.
|
||
(Contributed by Bénédikt Tran, Chris Markiewicz, and Adam Turner in :gh:`118761`.)
|
||
|
||
|
||
io
|
||
---
|
||
* :mod:`io` which provides the built-in :func:`open` makes less system calls
|
||
when opening regular files as well as reading whole files. Reading a small
|
||
operating system cached file in full is up to 15% faster.
|
||
:func:`pathlib.Path.read_bytes` has the most optimizations for reading a
|
||
file's bytes in full. (Contributed by Cody Maloney and Victor Stinner in
|
||
:gh:`120754` and :gh:`90102`.)
|
||
|
||
|
||
uuid
|
||
----
|
||
|
||
* Improve generation of :class:`~uuid.UUID` objects via their dedicated
|
||
functions:
|
||
|
||
* :func:`~uuid.uuid3` and :func:`~uuid.uuid5` are both roughly 40% faster
|
||
for 16-byte names and 20% faster for 1024-byte names. Performance for
|
||
longer names remains unchanged.
|
||
* :func:`~uuid.uuid4` and :func:`~uuid.uuid8` are 30% and 40% faster
|
||
respectively.
|
||
|
||
(Contributed by Bénédikt Tran in :gh:`128150`.)
|
||
|
||
|
||
zlib
|
||
----
|
||
|
||
* On Windows, ``zlib-ng`` is now used as the implementation of the
|
||
:mod:`zlib` module. This should produce compatible and comparable
|
||
results with better performance, though it is worth noting that
|
||
``zlib.Z_BEST_SPEED`` (1) may result in significantly less
|
||
compression than the previous implementation (while also significantly
|
||
reducing the time taken to compress).
|
||
(Contributed by Steve Dower in :gh:`91349`.)
|
||
|
||
|
||
Deprecated
|
||
==========
|
||
|
||
* :mod:`argparse`:
|
||
|
||
* Passing the undocumented keyword argument *prefix_chars* to
|
||
:meth:`~argparse.ArgumentParser.add_argument_group` is now
|
||
deprecated.
|
||
(Contributed by Savannah Ostrowski in :gh:`125563`.)
|
||
* Deprecated the :class:`argparse.FileType` type converter.
|
||
Anything with resource management should be done downstream after the
|
||
arguments are parsed.
|
||
(Contributed by Serhiy Storchaka in :gh:`58032`.)
|
||
|
||
* :mod:`asyncio`:
|
||
|
||
* :func:`!asyncio.iscoroutinefunction` is deprecated
|
||
and will be removed in Python 3.16;
|
||
use :func:`inspect.iscoroutinefunction` instead.
|
||
(Contributed by Jiahao Li and Kumar Aditya in :gh:`122875`.)
|
||
|
||
* :mod:`asyncio` policy system is deprecated and will be removed in Python 3.16.
|
||
In particular, the following classes and functions are deprecated:
|
||
|
||
* :class:`asyncio.AbstractEventLoopPolicy`
|
||
* :class:`asyncio.DefaultEventLoopPolicy`
|
||
* :class:`asyncio.WindowsSelectorEventLoopPolicy`
|
||
* :class:`asyncio.WindowsProactorEventLoopPolicy`
|
||
* :func:`asyncio.get_event_loop_policy`
|
||
* :func:`asyncio.set_event_loop_policy`
|
||
* :func:`asyncio.set_event_loop`
|
||
|
||
Users should use :func:`asyncio.run` or :class:`asyncio.Runner` with
|
||
*loop_factory* to use the desired event loop implementation.
|
||
|
||
For example, to use :class:`asyncio.SelectorEventLoop` on Windows::
|
||
|
||
import asyncio
|
||
|
||
async def main():
|
||
...
|
||
|
||
asyncio.run(main(), loop_factory=asyncio.SelectorEventLoop)
|
||
|
||
(Contributed by Kumar Aditya in :gh:`127949`.)
|
||
|
||
* :mod:`builtins`:
|
||
Passing a complex number as the *real* or *imag* argument in the
|
||
:func:`complex` constructor is now deprecated; it should only be passed
|
||
as a single positional argument.
|
||
(Contributed by Serhiy Storchaka in :gh:`109218`.)
|
||
|
||
* :mod:`codecs`:
|
||
:func:`codecs.open` is now deprecated. Use :func:`open` instead.
|
||
(Contributed by Inada Naoki in :gh:`133036`.)
|
||
|
||
* :mod:`ctypes`:
|
||
Calling :func:`ctypes.POINTER` on a string is deprecated.
|
||
Use :ref:`ctypes-incomplete-types` for self-referential structures.
|
||
Also, the internal ``ctypes._pointer_type_cache`` is deprecated.
|
||
See :func:`ctypes.POINTER` for updated implementation details.
|
||
(Contributed by Sergey Myrianov in :gh:`100926`.)
|
||
|
||
* :mod:`functools`:
|
||
Calling the Python implementation of :func:`functools.reduce` with *function*
|
||
or *sequence* as keyword arguments is now deprecated.
|
||
(Contributed by Kirill Podoprigora in :gh:`121676`.)
|
||
|
||
* :mod:`logging`:
|
||
Support for custom logging handlers with the *strm* argument is deprecated
|
||
and scheduled for removal in Python 3.16. Define handlers with the *stream*
|
||
argument instead. (Contributed by Mariusz Felisiak in :gh:`115032`.)
|
||
|
||
* :mod:`mimetypes`:
|
||
Valid extensions start with a '.' or are empty for
|
||
:meth:`mimetypes.MimeTypes.add_type`.
|
||
Undotted extensions are deprecated and will
|
||
raise a :exc:`ValueError` in Python 3.16.
|
||
(Contributed by Hugo van Kemenade in :gh:`75223`.)
|
||
|
||
* :mod:`!nturl2path`: This module is now deprecated. Call
|
||
:func:`urllib.request.url2pathname` and :func:`~urllib.request.pathname2url`
|
||
instead.
|
||
(Contributed by Barney Gale in :gh:`125866`.)
|
||
|
||
* :mod:`os`:
|
||
:term:`Soft deprecate <soft deprecated>` :func:`os.popen` and
|
||
:func:`os.spawn* <os.spawnl>` functions. They should no longer be used to
|
||
write new code. The :mod:`subprocess` module is recommended instead.
|
||
(Contributed by Victor Stinner in :gh:`120743`.)
|
||
|
||
* :mod:`pathlib`:
|
||
:meth:`!pathlib.PurePath.as_uri` is deprecated and will be removed in Python
|
||
3.19. Use :meth:`pathlib.Path.as_uri` instead.
|
||
(Contributed by Barney Gale in :gh:`123599`.)
|
||
|
||
* :mod:`pdb`:
|
||
The undocumented ``pdb.Pdb.curframe_locals`` attribute is now a deprecated
|
||
read-only property. The low overhead dynamic frame locals access added in
|
||
Python 3.13 by PEP 667 means the frame locals cache reference previously
|
||
stored in this attribute is no longer needed. Derived debuggers should access
|
||
``pdb.Pdb.curframe.f_locals`` directly in Python 3.13 and later versions.
|
||
(Contributed by Tian Gao in :gh:`124369` and :gh:`125951`.)
|
||
|
||
* :mod:`symtable`:
|
||
Deprecate :meth:`symtable.Class.get_methods` due to the lack of interest.
|
||
(Contributed by Bénédikt Tran in :gh:`119698`.)
|
||
|
||
* :mod:`tkinter`:
|
||
The :class:`!tkinter.Variable` methods :meth:`!trace_variable`,
|
||
:meth:`!trace_vdelete` and :meth:`!trace_vinfo` are now deprecated.
|
||
Use :meth:`!trace_add`, :meth:`!trace_remove` and :meth:`!trace_info`
|
||
instead.
|
||
(Contributed by Serhiy Storchaka in :gh:`120220`.)
|
||
|
||
* :mod:`urllib.parse`:
|
||
Accepting objects with false values (like ``0`` and ``[]``) except empty
|
||
strings, byte-like objects and ``None`` in :mod:`urllib.parse` functions
|
||
:func:`~urllib.parse.parse_qsl` and :func:`~urllib.parse.parse_qs` is now
|
||
deprecated.
|
||
(Contributed by Serhiy Storchaka in :gh:`116897`.)
|
||
|
||
.. Add deprecations above alphabetically, not here at the end.
|
||
|
||
.. include:: ../deprecations/pending-removal-in-3.15.rst
|
||
|
||
.. include:: ../deprecations/pending-removal-in-3.16.rst
|
||
|
||
.. include:: ../deprecations/pending-removal-in-3.17.rst
|
||
|
||
.. include:: ../deprecations/pending-removal-in-future.rst
|
||
|
||
Removed
|
||
=======
|
||
|
||
argparse
|
||
--------
|
||
|
||
* Remove the *type*, *choices*, and *metavar* parameters
|
||
of :class:`!argparse.BooleanOptionalAction`.
|
||
They were deprecated since 3.12.
|
||
|
||
* Calling :meth:`~argparse.ArgumentParser.add_argument_group` on an argument
|
||
group, and calling :meth:`~argparse.ArgumentParser.add_argument_group` or
|
||
:meth:`~argparse.ArgumentParser.add_mutually_exclusive_group` on a mutually
|
||
exclusive group now raise exceptions. This nesting was never supported,
|
||
often failed to work correctly, and was unintentionally exposed through
|
||
inheritance. This functionality has been deprecated since Python 3.11.
|
||
(Contributed by Savannah Ostrowski in :gh:`127186`.)
|
||
|
||
ast
|
||
---
|
||
|
||
* Remove the following classes. They were all deprecated since Python 3.8,
|
||
and have emitted deprecation warnings since Python 3.12:
|
||
|
||
* :class:`!ast.Bytes`
|
||
* :class:`!ast.Ellipsis`
|
||
* :class:`!ast.NameConstant`
|
||
* :class:`!ast.Num`
|
||
* :class:`!ast.Str`
|
||
|
||
Use :class:`ast.Constant` instead. As a consequence of these removals,
|
||
user-defined ``visit_Num``, ``visit_Str``, ``visit_Bytes``,
|
||
``visit_NameConstant`` and ``visit_Ellipsis`` methods on custom
|
||
:class:`ast.NodeVisitor` subclasses will no longer be called when the
|
||
:class:`!NodeVisitor` subclass is visiting an AST. Define a ``visit_Constant``
|
||
method instead.
|
||
|
||
Also, remove the following deprecated properties on :class:`ast.Constant`,
|
||
which were present for compatibility with the now-removed AST classes:
|
||
|
||
* :attr:`!ast.Constant.n`
|
||
* :attr:`!ast.Constant.s`
|
||
|
||
Use :attr:`!ast.Constant.value` instead.
|
||
(Contributed by Alex Waygood in :gh:`119562`.)
|
||
|
||
asyncio
|
||
-------
|
||
|
||
* Remove the following classes and functions. They were all deprecated and
|
||
emitted deprecation warnings since Python 3.12:
|
||
|
||
* :func:`!asyncio.get_child_watcher`
|
||
* :func:`!asyncio.set_child_watcher`
|
||
* :meth:`!asyncio.AbstractEventLoopPolicy.get_child_watcher`
|
||
* :meth:`!asyncio.AbstractEventLoopPolicy.set_child_watcher`
|
||
* :class:`!asyncio.AbstractChildWatcher`
|
||
* :class:`!asyncio.FastChildWatcher`
|
||
* :class:`!asyncio.MultiLoopChildWatcher`
|
||
* :class:`!asyncio.PidfdChildWatcher`
|
||
* :class:`!asyncio.SafeChildWatcher`
|
||
* :class:`!asyncio.ThreadedChildWatcher`
|
||
|
||
(Contributed by Kumar Aditya in :gh:`120804`.)
|
||
|
||
* Removed implicit creation of event loop by :func:`asyncio.get_event_loop`.
|
||
It now raises a :exc:`RuntimeError` if there is no current event loop.
|
||
(Contributed by Kumar Aditya in :gh:`126353`.)
|
||
|
||
There's a few patterns that use :func:`asyncio.get_event_loop`, most
|
||
of them can be replaced with :func:`asyncio.run`.
|
||
|
||
If you're running an async function, simply use :func:`asyncio.run`.
|
||
|
||
Before::
|
||
|
||
async def main():
|
||
...
|
||
|
||
|
||
loop = asyncio.get_event_loop()
|
||
try:
|
||
loop.run_until_complete(main())
|
||
finally:
|
||
loop.close()
|
||
|
||
After::
|
||
|
||
async def main():
|
||
...
|
||
|
||
asyncio.run(main())
|
||
|
||
If you need to start something, e.g. a server listening on a socket
|
||
and then run forever, use :func:`asyncio.run` and an
|
||
:class:`asyncio.Event`.
|
||
|
||
Before::
|
||
|
||
def start_server(loop):
|
||
...
|
||
|
||
loop = asyncio.get_event_loop()
|
||
try:
|
||
start_server(loop)
|
||
loop.run_forever()
|
||
finally:
|
||
loop.close()
|
||
|
||
After::
|
||
|
||
def start_server(loop):
|
||
...
|
||
|
||
async def main():
|
||
start_server(asyncio.get_running_loop())
|
||
await asyncio.Event().wait()
|
||
|
||
asyncio.run(main())
|
||
|
||
If you need to run something in an event loop, then run some blocking
|
||
code around it, use :class:`asyncio.Runner`.
|
||
|
||
Before::
|
||
|
||
async def operation_one():
|
||
...
|
||
|
||
def blocking_code():
|
||
...
|
||
|
||
async def operation_two():
|
||
...
|
||
|
||
loop = asyncio.get_event_loop()
|
||
try:
|
||
loop.run_until_complete(operation_one())
|
||
blocking_code()
|
||
loop.run_until_complete(operation_two())
|
||
finally:
|
||
loop.close()
|
||
|
||
After::
|
||
|
||
async def operation_one():
|
||
...
|
||
|
||
def blocking_code():
|
||
...
|
||
|
||
async def operation_two():
|
||
...
|
||
|
||
with asyncio.Runner() as runner:
|
||
runner.run(operation_one())
|
||
blocking_code()
|
||
runner.run(operation_two())
|
||
|
||
|
||
|
||
collections.abc
|
||
---------------
|
||
|
||
* Remove :class:`!collections.abc.ByteString`. It had previously raised a
|
||
:exc:`DeprecationWarning` since Python 3.12.
|
||
|
||
email
|
||
-----
|
||
|
||
* Remove the *isdst* parameter from :func:`email.utils.localtime`.
|
||
(Contributed by Hugo van Kemenade in :gh:`118798`.)
|
||
|
||
importlib
|
||
---------
|
||
|
||
* Remove deprecated :mod:`importlib.abc` classes:
|
||
|
||
* :class:`!importlib.abc.ResourceReader`
|
||
* :class:`!importlib.abc.Traversable`
|
||
* :class:`!importlib.abc.TraversableResources`
|
||
|
||
Use :mod:`importlib.resources.abc` classes instead:
|
||
|
||
* :class:`importlib.resources.abc.Traversable`
|
||
* :class:`importlib.resources.abc.TraversableResources`
|
||
|
||
(Contributed by Jason R. Coombs and Hugo van Kemenade in :gh:`93963`.)
|
||
|
||
itertools
|
||
---------
|
||
|
||
* Remove :mod:`itertools` support for copy, deepcopy, and pickle operations.
|
||
These had previously raised a :exc:`DeprecationWarning` since Python 3.12.
|
||
(Contributed by Raymond Hettinger in :gh:`101588`.)
|
||
|
||
pathlib
|
||
-------
|
||
|
||
* Remove support for passing additional keyword arguments to
|
||
:class:`pathlib.Path`. In previous versions, any such arguments are ignored.
|
||
* Remove support for passing additional positional arguments to
|
||
:meth:`pathlib.PurePath.relative_to` and
|
||
:meth:`~pathlib.PurePath.is_relative_to`. In previous versions, any such
|
||
arguments are joined onto *other*.
|
||
|
||
pkgutil
|
||
-------
|
||
|
||
* Remove deprecated :func:`!pkgutil.get_loader` and :func:`!pkgutil.find_loader`.
|
||
These had previously raised a :exc:`DeprecationWarning` since Python 3.12.
|
||
(Contributed by Bénédikt Tran in :gh:`97850`.)
|
||
|
||
pty
|
||
---
|
||
|
||
* Remove deprecated :func:`!pty.master_open` and :func:`!pty.slave_open`.
|
||
They had previously raised a :exc:`DeprecationWarning` since Python 3.12.
|
||
Use :func:`pty.openpty` instead.
|
||
(Contributed by Nikita Sobolev in :gh:`118824`.)
|
||
|
||
sqlite3
|
||
-------
|
||
|
||
* Remove :data:`!version` and :data:`!version_info` from :mod:`sqlite3`.
|
||
(Contributed by Hugo van Kemenade in :gh:`118924`.)
|
||
|
||
* Disallow using a sequence of parameters with named placeholders.
|
||
This had previously raised a :exc:`DeprecationWarning` since Python 3.12;
|
||
it will now raise a :exc:`sqlite3.ProgrammingError`.
|
||
(Contributed by Erlend E. Aasland in :gh:`118928` and :gh:`101693`.)
|
||
|
||
typing
|
||
------
|
||
|
||
* Remove :class:`!typing.ByteString`. It had previously raised a
|
||
:exc:`DeprecationWarning` since Python 3.12.
|
||
|
||
* :class:`typing.TypeAliasType` now supports star unpacking.
|
||
|
||
urllib
|
||
------
|
||
|
||
* Remove deprecated :class:`!Quoter` class from :mod:`urllib.parse`.
|
||
It had previously raised a :exc:`DeprecationWarning` since Python 3.11.
|
||
(Contributed by Nikita Sobolev in :gh:`118827`.)
|
||
* Remove deprecated :class:`!URLopener` and :class:`!FancyURLopener` classes
|
||
from :mod:`urllib.request`. They had previously raised a
|
||
:exc:`DeprecationWarning` since Python 3.3.
|
||
|
||
``myopener.open()`` can be replaced with :func:`~urllib.request.urlopen`,
|
||
and ``myopener.retrieve()`` can be replaced with
|
||
:func:`~urllib.request.urlretrieve`. Customizations to the opener
|
||
classes can be replaced by passing customized handlers to
|
||
:func:`~urllib.request.build_opener`.
|
||
(Contributed by Barney Gale in :gh:`84850`.)
|
||
|
||
Others
|
||
------
|
||
|
||
* Using :data:`NotImplemented` in a boolean context will now raise a :exc:`TypeError`.
|
||
It had previously raised a :exc:`DeprecationWarning` since Python 3.9. (Contributed
|
||
by Jelle Zijlstra in :gh:`118767`.)
|
||
|
||
* The :func:`int` built-in no longer delegates to
|
||
:meth:`~object.__trunc__`. Classes that want to support conversion to
|
||
integer must implement either :meth:`~object.__int__` or
|
||
:meth:`~object.__index__`. (Contributed by Mark Dickinson in :gh:`119743`.)
|
||
|
||
|
||
CPython Bytecode Changes
|
||
========================
|
||
|
||
* Replaced the opcode ``BINARY_SUBSCR`` by :opcode:`BINARY_OP` with oparg ``NB_SUBSCR``.
|
||
(Contributed by Irit Katriel in :gh:`100239`.)
|
||
|
||
Porting to Python 3.14
|
||
======================
|
||
|
||
This section lists previously described changes and other bugfixes
|
||
that may require changes to your code.
|
||
|
||
Changes in the Python API
|
||
-------------------------
|
||
|
||
* :class:`functools.partial` is now a method descriptor.
|
||
Wrap it in :func:`staticmethod` if you want to preserve the old behavior.
|
||
(Contributed by Serhiy Storchaka and Dominykas Grigonis in :gh:`121027`.)
|
||
|
||
* The :func:`locale.nl_langinfo` function now sets temporarily the ``LC_CTYPE``
|
||
locale in some cases.
|
||
This temporary change affects other threads.
|
||
(Contributed by Serhiy Storchaka in :gh:`69998`.)
|
||
|
||
* :class:`types.UnionType` is now an alias for :class:`typing.Union`,
|
||
causing changes in some behaviors.
|
||
See :ref:`above <whatsnew314-typing-union>` for more details.
|
||
(Contributed by Jelle Zijlstra in :gh:`105499`.)
|
||
|
||
|
||
Build changes
|
||
=============
|
||
|
||
* GNU Autoconf 2.72 is now required to generate :file:`configure`.
|
||
(Contributed by Erlend Aasland in :gh:`115765`.)
|
||
|
||
* ``#pragma``-based linking with ``python3*.lib`` can now be switched off
|
||
with :c:expr:`Py_NO_LINK_LIB`. (Contributed by Jean-Christophe
|
||
Fillion-Robin in :gh:`82909`.)
|
||
|
||
.. _whatsnew314-pep761:
|
||
|
||
PEP 761: Discontinuation of PGP signatures
|
||
------------------------------------------
|
||
|
||
PGP signatures will not be available for CPython 3.14 and onwards.
|
||
Users verifying artifacts must use `Sigstore verification materials`_ for
|
||
verifying CPython artifacts. This change in release process is specified
|
||
in :pep:`761`.
|
||
|
||
.. _Sigstore verification materials: https://www.python.org/downloads/metadata/sigstore/
|
||
|
||
|
||
C API changes
|
||
=============
|
||
|
||
New features
|
||
------------
|
||
|
||
* Add :c:func:`PyLong_GetSign` function to get the sign of :class:`int` objects.
|
||
(Contributed by Sergey B Kirpichev in :gh:`116560`.)
|
||
|
||
* Add a new :c:type:`PyUnicodeWriter` API to create a Python :class:`str`
|
||
object:
|
||
|
||
* :c:func:`PyUnicodeWriter_Create`
|
||
* :c:func:`PyUnicodeWriter_DecodeUTF8Stateful`
|
||
* :c:func:`PyUnicodeWriter_Discard`
|
||
* :c:func:`PyUnicodeWriter_Finish`
|
||
* :c:func:`PyUnicodeWriter_Format`
|
||
* :c:func:`PyUnicodeWriter_WriteChar`
|
||
* :c:func:`PyUnicodeWriter_WriteRepr`
|
||
* :c:func:`PyUnicodeWriter_WriteStr`
|
||
* :c:func:`PyUnicodeWriter_WriteSubstring`
|
||
* :c:func:`PyUnicodeWriter_WriteUCS4`
|
||
* :c:func:`PyUnicodeWriter_WriteUTF8`
|
||
* :c:func:`PyUnicodeWriter_WriteWideChar`
|
||
|
||
(Contributed by Victor Stinner in :gh:`119182`.)
|
||
|
||
* Add :c:func:`PyIter_NextItem` to replace :c:func:`PyIter_Next`,
|
||
which has an ambiguous return value.
|
||
(Contributed by Irit Katriel and Erlend Aasland in :gh:`105201`.)
|
||
|
||
* Add :c:func:`PyLong_IsPositive`, :c:func:`PyLong_IsNegative`
|
||
and :c:func:`PyLong_IsZero` for checking if :c:type:`PyLongObject`
|
||
is positive, negative, or zero, respectively.
|
||
(Contributed by James Roy and Sergey B Kirpichev in :gh:`126061`.)
|
||
|
||
* Add new functions to convert C ``<stdint.h>`` numbers from/to Python
|
||
:class:`int`:
|
||
|
||
* :c:func:`PyLong_AsInt32`
|
||
* :c:func:`PyLong_AsInt64`
|
||
* :c:func:`PyLong_AsUInt32`
|
||
* :c:func:`PyLong_AsUInt64`
|
||
* :c:func:`PyLong_FromInt32`
|
||
* :c:func:`PyLong_FromInt64`
|
||
* :c:func:`PyLong_FromUInt32`
|
||
* :c:func:`PyLong_FromUInt64`
|
||
|
||
(Contributed by Victor Stinner in :gh:`120389`.)
|
||
|
||
* Add :c:func:`PyBytes_Join(sep, iterable) <PyBytes_Join>` function,
|
||
similar to ``sep.join(iterable)`` in Python.
|
||
(Contributed by Victor Stinner in :gh:`121645`.)
|
||
|
||
* Add :c:func:`Py_HashBuffer` to compute and return the hash value of a buffer.
|
||
(Contributed by Antoine Pitrou and Victor Stinner in :gh:`122854`.)
|
||
|
||
* Add functions to get and set the current runtime Python configuration
|
||
(:pep:`741`):
|
||
|
||
* :c:func:`PyConfig_Get`
|
||
* :c:func:`PyConfig_GetInt`
|
||
* :c:func:`PyConfig_Set`
|
||
* :c:func:`PyConfig_Names`
|
||
|
||
(Contributed by Victor Stinner in :gh:`107954`.)
|
||
|
||
* Add functions to configure the Python initialization (:pep:`741`):
|
||
|
||
* :c:func:`Py_InitializeFromInitConfig`
|
||
* :c:func:`PyInitConfig_AddModule`
|
||
* :c:func:`PyInitConfig_Create`
|
||
* :c:func:`PyInitConfig_Free`
|
||
* :c:func:`PyInitConfig_FreeStrList`
|
||
* :c:func:`PyInitConfig_GetError`
|
||
* :c:func:`PyInitConfig_GetExitCode`
|
||
* :c:func:`PyInitConfig_GetInt`
|
||
* :c:func:`PyInitConfig_GetStr`
|
||
* :c:func:`PyInitConfig_GetStrList`
|
||
* :c:func:`PyInitConfig_HasOption`
|
||
* :c:func:`PyInitConfig_SetInt`
|
||
* :c:func:`PyInitConfig_SetStr`
|
||
* :c:func:`PyInitConfig_SetStrList`
|
||
|
||
(Contributed by Victor Stinner in :gh:`107954`.)
|
||
|
||
* Add a new import and export API for Python :class:`int` objects (:pep:`757`):
|
||
|
||
* :c:func:`PyLong_GetNativeLayout`;
|
||
* :c:func:`PyLong_Export`;
|
||
* :c:func:`PyLong_FreeExport`;
|
||
* :c:func:`PyLongWriter_Create`;
|
||
* :c:func:`PyLongWriter_Finish`;
|
||
* :c:func:`PyLongWriter_Discard`.
|
||
|
||
(Contributed by Sergey B Kirpichev and Victor Stinner in :gh:`102471`.)
|
||
|
||
* Add :c:func:`PyType_GetBaseByToken` and :c:data:`Py_tp_token` slot for easier
|
||
superclass identification, which attempts to resolve the `type checking issue
|
||
<https://peps.python.org/pep-0630/#type-checking>`__ mentioned in :pep:`630`
|
||
(:gh:`124153`).
|
||
|
||
* Add :c:func:`PyUnicode_Equal` function to the limited C API:
|
||
test if two strings are equal.
|
||
(Contributed by Victor Stinner in :gh:`124502`.)
|
||
|
||
* Add :c:func:`PyType_Freeze` function to make a type immutable.
|
||
(Contributed by Victor Stinner in :gh:`121654`.)
|
||
|
||
* Add :c:func:`PyUnstable_Object_EnableDeferredRefcount` for enabling
|
||
deferred reference counting, as outlined in :pep:`703`.
|
||
|
||
* Add :c:func:`PyMonitoring_FireBranchLeftEvent` and
|
||
:c:func:`PyMonitoring_FireBranchRightEvent` for generating
|
||
:monitoring-event:`BRANCH_LEFT` and :monitoring-event:`BRANCH_RIGHT`
|
||
events, respectively.
|
||
|
||
* Add :c:func:`Py_fopen` function to open a file. Similar to the
|
||
:c:func:`!fopen` function, but the *path* parameter is a Python object and an
|
||
exception is set on error. Add also :c:func:`Py_fclose` function to close a
|
||
file.
|
||
(Contributed by Victor Stinner in :gh:`127350`.)
|
||
|
||
* Add support of nullable arguments in :c:func:`PyArg_ParseTuple` and
|
||
similar functions.
|
||
Adding ``?`` after any format unit makes ``None`` be accepted as a value.
|
||
(Contributed by Serhiy Storchaka in :gh:`112068`.)
|
||
|
||
* The ``k`` and ``K`` formats in :c:func:`PyArg_ParseTuple` and
|
||
similar functions now use :meth:`~object.__index__` if available,
|
||
like all other integer formats.
|
||
(Contributed by Serhiy Storchaka in :gh:`112068`.)
|
||
|
||
* Add macros :c:func:`Py_PACK_VERSION` and :c:func:`Py_PACK_FULL_VERSION` for
|
||
bit-packing Python version numbers.
|
||
(Contributed by Petr Viktorin in :gh:`128629`.)
|
||
|
||
* Add :c:func:`PyUnstable_IsImmortal` for determining whether an object is :term:`immortal`,
|
||
for debugging purposes.
|
||
|
||
* Add :c:func:`PyImport_ImportModuleAttr` and
|
||
:c:func:`PyImport_ImportModuleAttrString` helper functions to import a module
|
||
and get an attribute of the module.
|
||
(Contributed by Victor Stinner in :gh:`128911`.)
|
||
|
||
* Add support for a new ``p`` format unit in :c:func:`Py_BuildValue` that allows to
|
||
take a C integer and produce a Python :class:`bool` object. (Contributed by
|
||
Pablo Galindo in :issue:`45325`.)
|
||
|
||
* Add :c:func:`PyUnstable_Object_IsUniqueReferencedTemporary` to determine if an object
|
||
is a unique temporary object on the interpreter's operand stack. This can
|
||
be used in some cases as a replacement for checking if :c:func:`Py_REFCNT`
|
||
is ``1`` for Python objects passed as arguments to C API functions.
|
||
|
||
|
||
Limited C API changes
|
||
---------------------
|
||
|
||
* In the limited C API 3.14 and newer, :c:func:`Py_TYPE` and
|
||
:c:func:`Py_REFCNT` are now implemented as an opaque function call to hide
|
||
implementation details.
|
||
(Contributed by Victor Stinner in :gh:`120600` and :gh:`124127`.)
|
||
|
||
* Remove the :c:macro:`PySequence_Fast_GET_SIZE`,
|
||
:c:macro:`PySequence_Fast_GET_ITEM` and :c:macro:`PySequence_Fast_ITEMS`
|
||
macros from the limited C API, since these macros never worked in the limited
|
||
C API. Keep :c:func:`PySequence_Fast` in the limited C API.
|
||
(Contributed by Victor Stinner in :gh:`91417`.)
|
||
|
||
|
||
Porting to Python 3.14
|
||
----------------------
|
||
|
||
* :c:func:`Py_Finalize` now deletes all interned strings. This
|
||
is backwards incompatible to any C-Extension that holds onto an interned
|
||
string after a call to :c:func:`Py_Finalize` and is then reused after a
|
||
call to :c:func:`Py_Initialize`. Any issues arising from this behavior will
|
||
normally result in crashes during the execution of the subsequent call to
|
||
:c:func:`Py_Initialize` from accessing uninitialized memory. To fix, use
|
||
an address sanitizer to identify any use-after-free coming from
|
||
an interned string and deallocate it during module shutdown.
|
||
(Contributed by Eddie Elizondo in :gh:`113601`.)
|
||
|
||
* The :ref:`Unicode Exception Objects <unicodeexceptions>` C API
|
||
now raises a :exc:`TypeError` if its exception argument is not
|
||
a :exc:`UnicodeError` object.
|
||
(Contributed by Bénédikt Tran in :gh:`127691`.)
|
||
|
||
.. _whatsnew314-refcount:
|
||
|
||
* The interpreter internally avoids some reference count modifications when
|
||
loading objects onto the operands stack by :term:`borrowing <borrowed reference>`
|
||
references when possible. This can lead to smaller reference count values
|
||
compared to previous Python versions. C API extensions that checked
|
||
:c:func:`Py_REFCNT` of ``1`` to determine if an function argument is not
|
||
referenced by any other code should instead use
|
||
:c:func:`PyUnstable_Object_IsUniqueReferencedTemporary` as a safer replacement.
|
||
|
||
|
||
* Private functions promoted to public C APIs:
|
||
|
||
* ``_PyBytes_Join()``: :c:func:`PyBytes_Join`.
|
||
* ``_PyLong_IsNegative()``: :c:func:`PyLong_IsNegative`.
|
||
* ``_PyLong_IsPositive()``: :c:func:`PyLong_IsPositive`.
|
||
* ``_PyLong_IsZero()``: :c:func:`PyLong_IsZero`.
|
||
* ``_PyLong_Sign()``: :c:func:`PyLong_GetSign`.
|
||
* ``_PyUnicodeWriter_Dealloc()``: :c:func:`PyUnicodeWriter_Discard`.
|
||
* ``_PyUnicodeWriter_Finish()``: :c:func:`PyUnicodeWriter_Finish`.
|
||
* ``_PyUnicodeWriter_Init()``: use :c:func:`PyUnicodeWriter_Create`.
|
||
* ``_PyUnicodeWriter_Prepare()``: (no replacement).
|
||
* ``_PyUnicodeWriter_PrepareKind()``: (no replacement).
|
||
* ``_PyUnicodeWriter_WriteChar()``: :c:func:`PyUnicodeWriter_WriteChar`.
|
||
* ``_PyUnicodeWriter_WriteStr()``: :c:func:`PyUnicodeWriter_WriteStr`.
|
||
* ``_PyUnicodeWriter_WriteSubstring()``: :c:func:`PyUnicodeWriter_WriteSubstring`.
|
||
* ``_PyUnicode_EQ()``: :c:func:`PyUnicode_Equal`.
|
||
* ``_PyUnicode_Equal()``: :c:func:`PyUnicode_Equal`.
|
||
* ``_Py_GetConfig()``: :c:func:`PyConfig_Get` and :c:func:`PyConfig_GetInt`.
|
||
* ``_Py_HashBytes()``: :c:func:`Py_HashBuffer`.
|
||
* ``_Py_fopen_obj()``: :c:func:`Py_fopen`.
|
||
|
||
The `pythoncapi-compat project`_ can be used to get most of these new
|
||
functions on Python 3.13 and older.
|
||
|
||
.. _pythoncapi-compat project: https://github.com/python/pythoncapi-compat/
|
||
|
||
|
||
.. _whatsnew314-c-api-deprecated:
|
||
|
||
Deprecated
|
||
----------
|
||
|
||
* The :c:macro:`!Py_HUGE_VAL` macro is :term:`soft deprecated`,
|
||
use :c:macro:`!Py_INFINITY` instead.
|
||
(Contributed by Sergey B Kirpichev in :gh:`120026`.)
|
||
|
||
* Macros :c:macro:`!Py_IS_NAN`, :c:macro:`!Py_IS_INFINITY`
|
||
and :c:macro:`!Py_IS_FINITE` are :term:`soft deprecated`,
|
||
use instead :c:macro:`!isnan`, :c:macro:`!isinf` and
|
||
:c:macro:`!isfinite` available from :file:`math.h`
|
||
since C99. (Contributed by Sergey B Kirpichev in :gh:`119613`.)
|
||
|
||
* Non-tuple sequences are deprecated as argument for the ``(items)``
|
||
format unit in :c:func:`PyArg_ParseTuple` and other
|
||
:ref:`argument parsing <arg-parsing>` functions if *items* contains
|
||
format units which store a :ref:`borrowed buffer <c-arg-borrowed-buffer>`
|
||
or a :term:`borrowed reference`.
|
||
(Contributed by Serhiy Storchaka in :gh:`50333`.)
|
||
|
||
* The previously undocumented function :c:func:`PySequence_In` is :term:`soft deprecated`.
|
||
Use :c:func:`PySequence_Contains` instead.
|
||
(Contributed by Yuki Kobayashi in :gh:`127896`.)
|
||
|
||
.. Add C API deprecations above alphabetically, not here at the end.
|
||
|
||
* The ``PyMonitoring_FireBranchEvent`` function is deprecated and should
|
||
be replaced with calls to :c:func:`PyMonitoring_FireBranchLeftEvent`
|
||
and :c:func:`PyMonitoring_FireBranchRightEvent`.
|
||
|
||
* The following private functions are deprecated and planned for removal in
|
||
Python 3.18:
|
||
|
||
* :c:func:`!_PyBytes_Join`: use :c:func:`PyBytes_Join`.
|
||
* :c:func:`!_PyDict_GetItemStringWithError`: use :c:func:`PyDict_GetItemStringRef`.
|
||
* :c:func:`!_PyDict_Pop()`: use :c:func:`PyDict_Pop`.
|
||
* :c:func:`!_PyLong_Sign()`: use :c:func:`PyLong_GetSign`.
|
||
* :c:func:`!_PyLong_FromDigits` and :c:func:`!_PyLong_New`:
|
||
use :c:func:`PyLongWriter_Create`.
|
||
* :c:func:`!_PyThreadState_UncheckedGet`: use :c:func:`PyThreadState_GetUnchecked`.
|
||
* :c:func:`!_PyUnicode_AsString`: use :c:func:`PyUnicode_AsUTF8`.
|
||
* :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:`!_Py_HashPointer`: use :c:func:`Py_HashPointer`.
|
||
* :c:func:`!_Py_fopen_obj`: use :c:func:`Py_fopen`.
|
||
|
||
The `pythoncapi-compat project`_ can be used to get these new public
|
||
functions on Python 3.13 and older.
|
||
(Contributed by Victor Stinner in :gh:`128863`.)
|
||
|
||
.. include:: ../deprecations/c-api-pending-removal-in-3.15.rst
|
||
|
||
.. include:: ../deprecations/c-api-pending-removal-in-3.18.rst
|
||
|
||
.. include:: ../deprecations/c-api-pending-removal-in-future.rst
|
||
|
||
|
||
.. _whatsnew314-c-api-removed:
|
||
|
||
Removed
|
||
-------
|
||
|
||
* Creating :c:data:`immutable types <Py_TPFLAGS_IMMUTABLETYPE>` with mutable
|
||
bases was deprecated since 3.12 and now raises a :exc:`TypeError`.
|
||
|
||
* Remove ``PyDictObject.ma_version_tag`` member which was deprecated since
|
||
Python 3.12. Use the :c:func:`PyDict_AddWatcher` API instead.
|
||
(Contributed by Sam Gross in :gh:`124296`.)
|
||
|
||
* Remove the private ``_Py_InitializeMain()`` function. It was a
|
||
:term:`provisional API` added to Python 3.8 by :pep:`587`.
|
||
(Contributed by Victor Stinner in :gh:`129033`.)
|
||
|
||
* The undocumented APIs :c:macro:`!Py_C_RECURSION_LIMIT` and
|
||
:c:member:`!PyThreadState.c_recursion_remaining`, added in 3.13, are removed
|
||
without a deprecation period.
|
||
Please use :c:func:`Py_EnterRecursiveCall` to guard against runaway recursion
|
||
in C code.
|
||
(Removed in :gh:`133079`, see also :gh:`130396`.)
|