Sync upstream CPython branch '3.14'

Summary:
Python `3.14.0rc3+` (`3.14`) was **published** on 2025-09-18 17:54:43+00:00.

# Commit Info

Base: (`3.14.0rc2+`) - `1c901860e621615ecf9b77400d6cfae2c975d93a` (commit date: 2025-09-16 09:10:53+00:00)
Imported: (`3.14.0rc3+`) - `a20395b899163b4d337107b2c4ca1f3cef467462` (commit date: 2025-09-18 17:54:43+00:00)

# Files added

```
Lib/test/test_pyrepl/eio_test_script.py
Misc/NEWS.d/3.14.0rc3.rst
Python/emscripten_trampoline_inner.c
Tools/wasm/emscripten/prepare_external_wasm.py
```

# Files removed

```
Misc/NEWS.d/next/Core_and_Builtins/2025-08-10-21-34-12.gh-issue-137576.0ZicS-.rst
Misc/NEWS.d/next/Core_and_Builtins/2025-08-14-14-18-29.gh-issue-137728.HdYS9R.rst
Misc/NEWS.d/next/Core_and_Builtins/2025-08-15-15-45-26.gh-issue-137079.YEow69.rst
Misc/NEWS.d/next/Core_and_Builtins/2025-08-17-13-36-53.gh-issue-137883.55VDCN.rst
Misc/NEWS.d/next/Core_and_Builtins/2025-08-22-11-39-40.gh-issue-137384.j4b_in.rst
Misc/NEWS.d/next/Core_and_Builtins/2025-09-01-13-54-43.gh-issue-138349.0fGmAi.rst
Misc/NEWS.d/next/Core_and_Builtins/2025-09-01-16-09-02.gh-issue-138318.t-WEN5.rst
Misc/NEWS.d/next/Core_and_Builtins/2025-09-02-09-10-06.gh-issue-138372.h1Xk4-.rst
Misc/NEWS.d/next/Core_and_Builtins/2025-09-03-17-00-30.gh-issue-138479.qUxgWs.rst
Misc/NEWS.d/next/Core_and_Builtins/2025-09-05-01-19-04.gh-issue-138192.erluq5.rst
Misc/NEWS.d/next/Core_and_Builtins/2025-09-10-14-53-59.gh-issue-71810.ppf0J-.rst
Misc/NEWS.d/next/Library/2025-06-01-11-14-00.gh-issue-134953.ashdfs.rst
Misc/NEWS.d/next/Library/2025-07-13-11-20-05.gh-issue-136134.xhh0Kq.rst
Misc/NEWS.d/next/Library/2025-07-13-13-31-22.gh-issue-136134.mh6VjS.rst
Misc/NEWS.d/next/Library/2025-08-16-18-11-41.gh-issue-90548.q3aJUK.rst
Misc/NEWS.d/next/Library/2025-08-18-16-02-51.gh-issue-134869.GnAjnU.rst
Misc/NEWS.d/next/Library/2025-08-30-10-58-15.gh-issue-138253.9Ehj-N.rst
Misc/NEWS.d/next/Library/2025-09-05-07-50-18.gh-issue-138515.E3M-pu.rst
Misc/NEWS.d/next/Library/2025-09-10-10-02-59.gh-issue-128636.ldRKGZ.rst
Misc/NEWS.d/next/Library/2025-09-12-01-01-05.gh-issue-138804.46ZukT.rst
Misc/NEWS.d/next/Security/2025-06-18-13-34-55.gh-issue-135661.NZlpWf.rst
Misc/NEWS.d/next/Tools-Demos/2025-08-21-14-04-50.gh-issue-137873.qxffLt.rst
```

Reviewed By: aleivag

Differential Revision: D82725277

fbshipit-source-id: 4b6bc890befa113050def917514eb3651bafae31

Author: itamaro

Doc/deprecations/c-api-pending-removal-in-3.18.rst

@@ -1,11 +1,12 @@
 Pending removal in Python 3.18
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-* Deprecated private functions (:gh:`128863`):
+* 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()`: :c:func:`PyDict_Pop`.
+  * :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`.
@@ -31,7 +32,7 @@ Pending removal in Python 3.18
     :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_WriteASCII(writer, str) <PyUnicodeWriter_WriteASCII>`.
   * :c:func:`!_PyUnicodeWriter_WriteLatin1String`:
     replace ``_PyUnicodeWriter_WriteLatin1String(&writer, str)`` with
     :c:func:`PyUnicodeWriter_WriteUTF8(writer, str) <PyUnicodeWriter_WriteUTF8>`.
@@ -41,5 +42,6 @@ Pending removal in Python 3.18
   * :c:func:`!_Py_fopen_obj`: use :c:func:`Py_fopen`.
 
   The `pythoncapi-compat project
-  <https://github.com/python/pythoncapi-compat/>`__ can be used to get these
-  new public functions on Python 3.13 and older.
+  <https://github.com/python/pythoncapi-compat/>`__ can be used to get
+  these new public functions on Python 3.13 and older.
+  (Contributed by Victor Stinner in :gh:`128863`.)

Doc/deprecations/pending-removal-in-3.14.rst

@@ -38,12 +38,6 @@ Pending removal in Python 3.14
     is no current event loop set and it decides to create one.
     (Contributed by Serhiy Storchaka and Guido van Rossum in :gh:`100160`.)
 
-* :mod:`collections.abc`: Deprecated :class:`!collections.abc.ByteString`.
-  Prefer :class:`!Sequence` or :class:`~collections.abc.Buffer`.
-  For use in typing, prefer a union, like ``bytes | bytearray``,
-  or :class:`collections.abc.Buffer`.
-  (Contributed by Shantanu Jain in :gh:`91896`.)
-
 * :mod:`email`: Deprecated the *isdst* parameter in :func:`email.utils.localtime`.
   (Contributed by Alan Williams in :gh:`72346`.)
 
@@ -96,9 +90,6 @@ Pending removal in Python 3.14
     if :ref:`named placeholders <sqlite3-placeholders>` are used and
     *parameters* is a sequence instead of a :class:`dict`.
 
-* :mod:`typing`: :class:`!typing.ByteString`, deprecated since Python 3.9,
-  now causes a :exc:`DeprecationWarning` to be emitted when it is used.
-
 * :mod:`urllib`:
   :class:`!urllib.parse.Quoter` is deprecated: it was not intended to be a
   public API.

Doc/deprecations/pending-removal-in-3.17.rst

@@ -1,10 +1,51 @@
 Pending removal in Python 3.17
 ------------------------------
 
+* :mod:`collections.abc`:
+
+  - :class:`collections.abc.ByteString` is scheduled for removal in Python 3.17.
+
+    Use ``isinstance(obj, collections.abc.Buffer)`` to test if ``obj``
+    implements the :ref:`buffer protocol <bufferobjects>` at runtime. For use
+    in type annotations, either use :class:`~collections.abc.Buffer` or a union
+    that explicitly specifies the types your code supports (e.g.,
+    ``bytes | bytearray | memoryview``).
+
+    :class:`!ByteString` was originally intended to be an abstract class that
+    would serve as a supertype of both :class:`bytes` and :class:`bytearray`.
+    However, since the ABC never had any methods, knowing that an object was an
+    instance of :class:`!ByteString` never actually told you anything useful
+    about the object. Other common buffer types such as :class:`memoryview`
+    were also never understood as subtypes of :class:`!ByteString` (either at
+    runtime or by static type checkers).
+
+    See :pep:`PEP 688 <688#current-options>` for more details.
+    (Contributed by Shantanu Jain in :gh:`91896`.)
+
+
 * :mod:`typing`:
 
   - Before Python 3.14, 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.
+  - :class:`typing.ByteString`, deprecated since Python 3.9, is scheduled for removal in
+    Python 3.17.
+
+    Use ``isinstance(obj, collections.abc.Buffer)`` to test if ``obj``
+    implements the :ref:`buffer protocol <bufferobjects>` at runtime. For use
+    in type annotations, either use :class:`~collections.abc.Buffer` or a union
+    that explicitly specifies the types your code supports (e.g.,
+    ``bytes | bytearray | memoryview``).
+
+    :class:`!ByteString` was originally intended to be an abstract class that
+    would serve as a supertype of both :class:`bytes` and :class:`bytearray`.
+    However, since the ABC never had any methods, knowing that an object was an
+    instance of :class:`!ByteString` never actually told you anything useful
+    about the object. Other common buffer types such as :class:`memoryview`
+    were also never understood as subtypes of :class:`!ByteString` (either at
+    runtime or by static type checkers).
+
+    See :pep:`PEP 688 <688#current-options>` for more details.
+    (Contributed by Shantanu Jain in :gh:`91896`.)

Doc/library/argparse.rst

@@ -774,16 +774,16 @@ how the command-line arguments should be handled. The supplied actions are:
     >>> parser.parse_args('--foo --bar'.split())
     Namespace(foo=True, bar=False, baz=True)
 
-* ``'append'`` - This stores a list, and appends each argument value to the
-  list. It is useful to allow an option to be specified multiple times.
-  If the default value is non-empty, the default elements will be present
-  in the parsed value for the option, with any values from the
-  command line appended after those default values. Example usage::
+* ``'append'`` - This appends each argument value to a list.
+  It is useful for allowing an option to be specified multiple times.
+  If the default value is a non-empty list, the parsed value will start
+  with the default list's elements and any values from the command line
+  will be appended after those default values. Example usage::
 
     >>> parser = argparse.ArgumentParser()
-    >>> parser.add_argument('--foo', action='append')
+    >>> parser.add_argument('--foo', action='append', default=['0'])
     >>> parser.parse_args('--foo 1 --foo 2'.split())
-    Namespace(foo=['1', '2'])
+    Namespace(foo=['0', '1', '2'])
 
 * ``'append_const'`` - This stores a list, and appends the value specified by
   the const_ keyword argument to the list; note that the const_ keyword
@@ -981,8 +981,8 @@ the various :class:`ArgumentParser` actions.  The two most common uses of it are
   (like ``-f`` or ``--foo``) and ``nargs='?'``.  This creates an optional
   argument that can be followed by zero or one command-line arguments.
   When parsing the command line, if the option string is encountered with no
-  command-line argument following it, the value of ``const`` will be assumed to
-  be ``None`` instead.  See the nargs_ description for examples.
+  command-line argument following it, the value from ``const`` will be used.
+  See the nargs_ description for examples.
 
 .. versionchanged:: 3.11
    ``const=None`` by default, including when ``action='append_const'`` or
@@ -1142,16 +1142,21 @@ if the argument was not one of the acceptable values::
    game.py: error: argument move: invalid choice: 'fire' (choose from 'rock',
    'paper', 'scissors')
 
-Note that inclusion in the *choices* sequence is checked after any type_
-conversions have been performed, so the type of the objects in the *choices*
-sequence should match the type_ specified.
-
 Any sequence can be passed as the *choices* value, so :class:`list` objects,
 :class:`tuple` objects, and custom sequences are all supported.
 
 Use of :class:`enum.Enum` is not recommended because it is difficult to
 control its appearance in usage, help, and error messages.
 
+Note that *choices* are checked after any type_
+conversions have been performed, so objects in *choices*
+should match the type_ specified. This can make *choices*
+appear unfamiliar in usage, help, or error messages.
+
+To keep *choices* user-friendly, consider a custom type wrapper that
+converts and formats values, or omit type_ and handle conversion in
+your application code.
+
 Formatted choices override the default *metavar* which is normally derived
 from *dest*.  This is usually what you want because the user never sees the
 *dest* parameter.  If this display isn't desirable (perhaps because there are

Doc/library/collections.abc.rst

@@ -140,6 +140,9 @@ ABC                            Inherits from          Abstract Methods        Mi
                                                       ``__len__``,
                                                       ``insert``
 
+:class:`ByteString`            :class:`Sequence`      ``__getitem__``,        Inherited :class:`Sequence` methods
+                                                      ``__len__``
+
 :class:`Set`                   :class:`Collection`    ``__contains__``,       ``__le__``, ``__lt__``, ``__eq__``, ``__ne__``,
                                                       ``__iter__``,           ``__gt__``, ``__ge__``, ``__and__``, ``__or__``,
                                                       ``__len__``             ``__sub__``, ``__rsub__``, ``__xor__``, ``__rxor__``
@@ -260,6 +263,7 @@ Collections Abstract Base Classes -- Detailed Descriptions
 
 .. class:: Sequence
            MutableSequence
+           ByteString
 
    ABCs for read-only and mutable :term:`sequences <sequence>`.
 
@@ -285,6 +289,25 @@ Collections Abstract Base Classes -- Detailed Descriptions
          The :meth:`~sequence.index` method gained support for
          the *stop* and *start* arguments.
 
+   .. deprecated-removed:: 3.12 3.17
+      The :class:`ByteString` ABC has been deprecated.
+
+      Use ``isinstance(obj, collections.abc.Buffer)`` to test if ``obj``
+      implements the :ref:`buffer protocol <bufferobjects>` at runtime. For use
+      in type annotations, either use :class:`Buffer` or a union that
+      explicitly specifies the types your code supports (e.g.,
+      ``bytes | bytearray | memoryview``).
+
+      :class:`!ByteString` was originally intended to be an abstract class that
+      would serve as a supertype of both :class:`bytes` and :class:`bytearray`.
+      However, since the ABC never had any methods, knowing that an object was
+      an instance of :class:`!ByteString` never actually told you anything
+      useful about the object. Other common buffer types such as
+      :class:`memoryview` were also never understood as subtypes of
+      :class:`!ByteString` (either at runtime or by static type checkers).
+
+      See :pep:`PEP 688 <688#current-options>` for more details.
+
 .. class:: Set
            MutableSet
 

Doc/library/getpass.rst

@@ -27,9 +27,9 @@ The :mod:`getpass` module provides two functions:
 
    The *echo_char* argument controls how user input is displayed while typing.
    If *echo_char* is ``None`` (default), input remains hidden. Otherwise,
-   *echo_char* must be a printable ASCII string and each typed character
-   is replaced by it. For example, ``echo_char='*'`` will display
-   asterisks instead of the actual input.
+   *echo_char* must be a single printable ASCII character and each
+   typed character is replaced by it. For example, ``echo_char='*'`` will
+   display asterisks instead of the actual input.
 
    If echo free input is unavailable getpass() falls back to printing
    a warning message to *stream* and reading from ``sys.stdin`` and

Doc/library/html.rst

@@ -14,9 +14,12 @@ This module defines utilities to manipulate HTML.
 
    Convert the characters ``&``, ``<`` and ``>`` in string *s* to HTML-safe
    sequences.  Use this if you need to display text that might contain such
-   characters in HTML.  If the optional flag *quote* is true, the characters
-   (``"``) and (``'``) are also translated; this helps for inclusion in an HTML
-   attribute value delimited by quotes, as in ``<a href="...">``.
+   characters in HTML.  If the optional flag *quote* is true (the default), the
+   characters (``"``) and (``'``) are also translated; this helps for inclusion
+   in an HTML attribute value delimited by quotes, as in ``<a href="...">``.
+   If *quote* is set to false, the characters (``"``) and (``'``) are not
+   translated.
+
 
    .. versionadded:: 3.2
 

Doc/library/imaplib.rst

@@ -413,7 +413,7 @@ An :class:`IMAP4` instance has the following methods:
    the password.  Will only work if the server ``CAPABILITY`` response includes the
    phrase ``AUTH=CRAM-MD5``.
 
-   .. versionchanged:: next
+   .. versionchanged:: 3.14
       An :exc:`IMAP4.error` is raised if MD5 support is not available.
 
 

Doc/library/inspect.rst

@@ -253,6 +253,9 @@ attributes (see :ref:`import-mod-attrs` for module attributes):
 +-----------------+-------------------+---------------------------+
 |                 | gi_running        | is the generator running? |
 +-----------------+-------------------+---------------------------+
+|                 | gi_suspended      | is the generator          |
+|                 |                   | suspended?                |
++-----------------+-------------------+---------------------------+
 |                 | gi_code           | code                      |
 +-----------------+-------------------+---------------------------+
 |                 | gi_yieldfrom      | object being iterated by  |

Doc/library/logging.rst

@@ -671,16 +671,15 @@ Formatter Objects
        which is just the logged message.
    :type fmt: str
 
-   :param datefmt: A format string in the given *style* for
-       the date/time portion of the logged output.
+   :param datefmt: A format string for the date/time portion of the logged output.
        If not specified, the default described in :meth:`formatTime` is used.
    :type datefmt: str
 
    :param style: Can be one of ``'%'``, ``'{'`` or ``'$'`` and determines
        how the format string will be merged with its data: using one of
        :ref:`old-string-formatting` (``%``), :meth:`str.format` (``{``)
        or :class:`string.Template` (``$``). This only applies to
-       *fmt* and *datefmt* (e.g. ``'%(message)s'`` versus ``'{message}'``),
+       *fmt* (e.g. ``'%(message)s'`` versus ``'{message}'``),
        not to the actual log messages passed to the logging methods.
        However, there are :ref:`other ways <formatting-styles>`
        to use ``{``- and ``$``-formatting for log messages.