Sync pre-release CPython main branch from GitHub (2026-10-14)

Summary:
Imported python/cpython `3.16.0a1+dev` from upstream rev [`32fd69b`](https://www.github.com/python/cpython/commit/32fd69bdea00ce4dc24959734cc0d9284eb52f1e) (committed 2026-10-14 03:36:44+00:00).

# Commit Info

- Base: (`3.16.0a0`) - [`c6c0608`](https://www.github.com/python/cpython/commit/c6c060843b7635b5a1f82e0983d803eb0d185b5d) (commit date: 2026-10-10 23:12:35+00:00)
- Imported: (`3.16.0a1+dev`) - [`32fd69b`](https://www.github.com/python/cpython/commit/32fd69bdea00ce4dc24959734cc0d9284eb52f1e) (commit date: 2026-10-14 03:36:44+00:00)

# Noteworthy file changes

- Test files (1 added)
- Low-signal files (7 added, 1055 removed) (NEWS.d, docs, .github)

Complete list of added/removed files: https://www.internalfb.com/intern/everpaste/?color=0&handle=GJksrjALCZsXUaYFAFf1r5rhevhbbr0LAAAz

Reviewed By: itamaro

Differential Revision: D125154486

fbshipit-source-id: 4119629a1aaab74a61eaad8d8a149fd507193e44

Author: generatedunixname1734921407115435

Doc/builtins/functions.rst

@@ -110,7 +110,7 @@ are always available.  They are listed here in alphabetical order.
 
    .. versionadded:: 3.10
 
-   .. versionchanged:: next
+   .. versionchanged:: 3.16
       Added the *stop_value* and *stop_exception* parameters.
 
 .. function:: all(iterable, /)
@@ -1241,7 +1241,7 @@ are always available.  They are listed here in alphabetical order.
       for item in iter(input_queue.get_nowait, stop_exception=queue.Empty):
           process_item(item)
 
-   .. versionchanged:: next
+   .. versionchanged:: 3.16
       Added the *stop_exception* parameter
       and allowed passing *stop_value* by keyword.
 

Doc/builtins/stdtypes.rst

@@ -5254,7 +5254,7 @@ copying.
       .. versionchanged:: 3.5
          The source format is no longer restricted when casting to a byte view.
 
-      .. versionchanged:: next
+      .. versionchanged:: 3.16
          Casting a multi-dimensional F-contiguous view to a one-dimensional
          view is now supported.
 
@@ -5331,7 +5331,7 @@ copying.
 
       .. versionadded:: 3.3
 
-      .. versionchanged:: next
+      .. versionchanged:: 3.16
          Added the *order* parameter.
 
    .. attribute:: readonly

Doc/c-api/capsule.rst

@@ -119,7 +119,7 @@ Refer to :ref:`using-capsules` for more information on using these objects.
    .. versionchanged:: 3.3
       *no_block* has no effect anymore.
 
-   .. versionchanged:: next
+   .. versionchanged:: 3.16
       Submodules are now imported if needed.
 
 

Doc/c-api/complex.rst

@@ -198,5 +198,5 @@ the :ref:`Number Protocol <number>` API or use native complex types, like
 
    .. deprecated:: 3.15
 
-   .. versionchanged:: next
+   .. versionchanged:: 3.16
       This function leaves :c:data:`errno` unchanged on success.

Doc/c-api/import.rst

@@ -417,6 +417,10 @@ Importing Modules
    (Custom importers should do this in their
    :py:meth:`~importlib.abc.Loader.exec_module` method.)
 
+   If the spec's name is dotted and *initfunc* creates the module using only
+   the last component of the name, the module's :attr:`~module.__name__`
+   is set to the full name from the spec.
+
    On error, return NULL with an exception set.
 
    .. versionadded:: 3.15

Doc/c-api/init_config.rst

@@ -123,7 +123,7 @@ Error Handling
    Python 3.16. Instead, the option is now processed in :c:func:`Py_RunMain`.
    This function became useless.
 
-   .. deprecated:: next
+   .. deprecated:: 3.16
 
 
 Get Options
@@ -247,7 +247,7 @@ Initialize Python
    * Return ``0`` on success.
    * Set an error in *config* and return ``-1`` on error.
 
-   .. versionchanged:: next
+   .. versionchanged:: 3.16
       The function no longer sets an exit code if a command line option wants
       to exit Python. Instead, the option is now processed in
       :c:func:`Py_RunMain`.
@@ -623,7 +623,7 @@ Some options are read from the :mod:`sys` attributes. For example, the option
 
    .. versionadded:: 3.14
 
-   .. versionchanged:: next
+   .. versionchanged:: 3.16
       The function now replaces :data:`sys.flags` (create a new object),
       instead of modifying :data:`sys.flags` in-place.
 
@@ -755,7 +755,7 @@ PyStatus
 
       Exit code. Argument passed to ``exit()``.
 
-      .. deprecated:: next
+      .. deprecated:: 3.16
 
    .. c:member:: const char *err_msg
 
@@ -787,7 +787,7 @@ PyStatus
 
       Exit Python with the specified exit code.
 
-      .. deprecated:: next
+      .. deprecated:: 3.16
          :c:func:`Py_InitializeFromConfig` no longer sets an exit code if a
          command line option wants to exit Python. Instead, the option is
          now processed in :c:func:`Py_RunMain`.
@@ -807,7 +807,7 @@ PyStatus
 
       Is the result an exit?
 
-      .. deprecated:: next
+      .. deprecated:: 3.16
          :c:func:`Py_InitializeFromConfig` no longer sets an exit code if a
          command line option wants to exit Python. Instead, the option is
          now processed in :c:func:`Py_RunMain`.

Doc/c-api/interp-lifecycle.rst

@@ -127,7 +127,7 @@ Initializing and finalizing the interpreter
    interpreter, populating the runtime configuration structure, and querying
    the returned status structure.
 
-   .. versionchanged:: next
+   .. versionchanged:: 3.16
       The function no longer returns an exit code if a command line option
       wants to exit Python. Instead, the option is processed in
       :c:func:`Py_RunMain`.

Doc/c-api/marshal.rst

@@ -24,7 +24,7 @@ The following exceptions can be raised by these functions:
 :exc:`KeyboardInterrupt` if reading or writing is interrupted by a signal,
 and :exc:`MemoryError` if memory allocation fails.
 
-.. versionchanged:: next
+.. versionchanged:: 3.16
    Previously, in functions taking a :c:expr:`FILE*`,
    the reading functions raised :exc:`EOFError`
    instead of :exc:`OSError` and :exc:`KeyboardInterrupt`,
@@ -43,14 +43,40 @@ and :exc:`MemoryError` if memory allocation fails.
    This function can fail, in which case it sets the error indicator.
    Use :c:func:`PyErr_Occurred` to check for that.
 
+   .. note::
+
+      In Python 3.15 and earlier, this function does not set the error
+      indicator if writing to *file* fails.
+      The same caveat applies as for :c:func:`PyMarshal_WriteObjectToFile`.
+
 .. c:function:: void PyMarshal_WriteObjectToFile(PyObject *value, FILE *file, int version)
 
    Marshal a Python object, *value*, to *file*.
    *version* indicates the file format.
 
+   The marshalled representation of *value* is built in memory
+   and then written to *file*.
+   Nothing is written if *value* cannot be marshalled.
+
    This function can fail, in which case it sets the error indicator.
    Use :c:func:`PyErr_Occurred` to check for that.
 
+   .. note::
+
+      In Python 3.15 and earlier, this function can write only part of the
+      data to *file* and return without setting the error indicator, for
+      example if *value* contains an object which cannot be marshalled or
+      if writing to *file* fails (see :gh:`155907`).
+      Code which has to support these versions cannot rely on
+      :c:func:`PyErr_Occurred` alone to know that all the data was written.
+      It can use :c:func:`PyMarshal_WriteObjectToString` and write the
+      result itself, or validate what was written.
+
+   .. versionchanged:: 3.16
+      Previously, the data was written to *file* as it was produced,
+      using a buffer of constant size,
+      and incomplete data was written if *value* could not be marshalled.
+
 .. c:function:: PyObject* PyMarshal_WriteObjectToString(PyObject *value, int version)
 
    Return a bytes object containing the marshalled representation of *value*.

Doc/c-api/unicode.rst

@@ -1945,7 +1945,7 @@ Python does not always check these requirements.
 
    .. versionadded:: 3.3
 
-   .. soft-deprecated:: next
+   .. soft-deprecated:: 3.16
       See :ref:`pyunicode-new-mutating`.
 
 
@@ -1968,7 +1968,7 @@ Python does not always check these requirements.
 
    .. versionadded:: 3.3
 
-   .. soft-deprecated:: next
+   .. soft-deprecated:: 3.16
       Use the :c:type:`PyUnicodeWriter` API instead.
 
 
@@ -1988,7 +1988,7 @@ Python does not always check these requirements.
 
    .. versionadded:: 3.3
 
-   .. soft-deprecated:: next
+   .. soft-deprecated:: 3.16
       Use the :c:type:`PyUnicodeWriter` API instead.
 
 
@@ -2009,7 +2009,7 @@ Python does not always check these requirements.
    *\*unicode* must not be "used" yet.
    See :ref:`pyunicode-new-mutating` for details.
 
-   .. soft-deprecated:: next
+   .. soft-deprecated:: 3.16
       Use the :c:type:`PyUnicodeWriter` API instead.
 
 
@@ -2030,7 +2030,7 @@ Python does not always check these requirements.
 
    .. versionadded:: 3.3
 
-   .. soft-deprecated:: next
+   .. soft-deprecated:: 3.16
       Use the :c:type:`PyUnicodeWriter` API instead.
 
 
@@ -2050,5 +2050,5 @@ Python does not always check these requirements.
 
    .. versionadded:: 3.3
 
-   .. soft-deprecated:: next
+   .. soft-deprecated:: 3.16
       Use the :c:type:`PyUnicodeWriter` API instead.

Doc/c-api/weakref.rst

@@ -45,7 +45,7 @@ as much as it can.
    weakly referenceable object, or if *callback* is not callable, ``None``, or
    ``NULL``, this will raise :exc:`TypeError` and return ``NULL``.
 
-   .. versionchanged:: next
+   .. versionchanged:: 3.16
       Raise :exc:`!TypeError` if *callback* is not callable, ``None``, or
       ``NULL``.
 
@@ -65,7 +65,7 @@ as much as it can.
    is not a weakly referenceable object, or if *callback* is not callable,
    ``NULL``, this will raise :exc:`TypeError` and return ``NULL``.
 
-   .. versionchanged:: next
+   .. versionchanged:: 3.16
       Raise :exc:`!TypeError` if *callback* is not callable, ``None``, or
       ``NULL``.