Sync pre-release CPython main branch from GitHub (2026-08-07)

Summary:
Imported python/cpython `3.16.0a0` from upstream rev [`af930c1`](https://www.github.com/python/cpython/commit/af930c13787a15c22187d5d526f74f35c95f8056) (committed 2026-08-07 04:09:28+00:00).

# Commit Info

- Base: (`3.16.0a0`) - [`d2f4649`](https://www.github.com/python/cpython/commit/d2f464959287c91dd4365d69ab99022f20e3b64a) (commit date: 2026-08-06 01:59:28+00:00)
- Imported: (`3.16.0a0`) - [`af930c1`](https://www.github.com/python/cpython/commit/af930c13787a15c22187d5d526f74f35c95f8056) (commit date: 2026-08-07 04:09:28+00:00)

# Noteworthy file changes

- Low-signal files (2 added) (NEWS.d, docs, .github)

Complete list of added/removed files: https://www.internalfb.com/intern/everpaste/?color=0&handle=GF7A7CcNf4u7PD4GAKjqPRRX1u9hbr0LAAAz

Reviewed By: itamaro

Differential Revision: D115155377

fbshipit-source-id: fe8d10872eedd4ace7f28d4270eafe2d8d2d6a22

Author: generatedunixname1734921407115435

Doc/c-api/arg.rst

@@ -399,13 +399,18 @@ inside nested parentheses.  They are:
    their default value --- when an optional argument is not specified,
    :c:func:`PyArg_ParseTuple` does not touch the contents of the corresponding C
    variable(s).
+   For example, the format string ``"OO|OO"`` corresponds to the Python
+   signature ``f(a, b, c=None, d=None)``.
 
 ``$``
    :c:func:`PyArg_ParseTupleAndKeywords` only:
    Indicates that the remaining arguments in the Python argument list are
-   keyword-only.  Currently, all keyword-only arguments must also be optional
-   arguments, so ``|`` must always be specified before ``$`` in the format
-   string.
+   keyword-only.
+   They are optional if ``|`` was specified before ``$``, and required otherwise.
+   ``|`` cannot be specified after ``$``.
+   For example, the format string ``"O|O$O"`` corresponds to the Python
+   signature ``f(a, b=None, *, c=None)``,
+   and the format string ``"OO$OO"`` corresponds to ``f(a, b, *, c, d)``.
 
    .. versionadded:: 3.3
 

Doc/c-api/frame.rst

@@ -243,41 +243,3 @@ Unless using :pep:`523`, you will not need this.
    Return the currently executing line number, or -1 if there is no line number.
 
    .. versionadded:: 3.12
-
-
-.. c:var:: const PyTypeObject *PyUnstable_ExecutableKinds
-
-   An array of executable kinds (executor types) for frames, used for internal
-   debugging and tracing.
-
-   Tools like debuggers and profilers can use this to identify the type of execution
-   context associated with a frame (such as to filter out internal frames).
-   The entries are indexed by the following constants:
-
-   .. list-table::
-      :header-rows: 1
-      :widths: auto
-
-      * - Constant
-        - Description
-      * - .. c:macro:: PyUnstable_EXECUTABLE_KIND_SKIP
-        - The frame is internal (For example: inlined) and should be skipped by tools.
-      * - .. c:macro:: PyUnstable_EXECUTABLE_KIND_PY_FUNCTION
-        - The frame corresponds to a standard Python function.
-      * - .. c:macro:: PyUnstable_EXECUTABLE_KIND_BUILTIN_FUNCTION
-        - The frame corresponds to a function defined in native code.
-      * - .. c:macro:: PyUnstable_EXECUTABLE_KIND_METHOD_DESCRIPTOR
-        - The frame corresponds to a method on a class instance.
-
-   Note that reading the executable kind from a frame is currently only
-   possible with undocumented internal APIs.
-
-   .. versionadded:: 3.13
-
-
-.. c:macro:: PyUnstable_EXECUTABLE_KINDS
-
-   The number of entries in :c:data:`PyUnstable_ExecutableKinds`.
-
-   .. versionadded:: 3.13
-

Doc/tools/removed-ids.txt

@@ -23,6 +23,13 @@ using/configure.html: cmdoption-with-system-libmpdec
 library/symtable.html: symtable.Class.get_methods
 library/sys.html: sys._enablelegacywindowsfsencoding
 c-api/import.html: c.PyImport_LazyImportsMode.PyImport_LAZY_NONE
+c-api/frame.html: c.PyUnstable_EXECUTABLE_KINDS
+c-api/frame.html: c.PyUnstable_ExecutableKinds
+c-api/frame.html: c.PyUnstable_ExecutableKinds.PyUnstable_EXECUTABLE_KIND_BUILTIN_FUNCTION
+c-api/frame.html: c.PyUnstable_ExecutableKinds.PyUnstable_EXECUTABLE_KIND_METHOD_DESCRIPTOR
+c-api/frame.html: c.PyUnstable_ExecutableKinds.PyUnstable_EXECUTABLE_KIND_PY_FUNCTION
+c-api/frame.html: c.PyUnstable_ExecutableKinds.PyUnstable_EXECUTABLE_KIND_SKIP
+
 
 ## Old names for grammar tokens
 reference/expressions.html: grammar-token-python-grammar-comp_for

Doc/tools/templates/indexcontent.html

@@ -82,10 +82,16 @@ <h1>{{ docstitle|e }}</h1>
   <p><strong>{% trans %}Other resources:{% endtrans %}</strong></p>
   <div class="contentstable">
     <ul>
+      <li class="biglink"><a class="biglink" href="https://devguide.python.org">{% trans %}Python developer's guide{% endtrans %}</a><br>
+         <span class="linkdescr">{% trans %}Information on contributing to Python{% endtrans %}</span></li>
       <li class="biglink"><a class="biglink" href="https://packaging.python.org">{% trans %}Python Packaging User Guide{% endtrans %}</a><br>
          <span class="linkdescr">{% trans %}Resources relating to Python packaging{% endtrans %}</span></li>
+      <li class="biglink"><a class="biglink" href="https://www.python.org/doc/av/">{% trans %}Audio/visual talks{% endtrans %}</a><br>
+         <span class="linkdescr">{% trans %}Podcasts, talks, and video presentations from the community{% endtrans %}</span></li>
     </ul>
     <ul>
+      <li class="biglink"><a class="biglink" href="https://peps.python.org/">{% trans %}Python Enhancement Proposals{% endtrans %}</a><br>
+         <span class="linkdescr">{% trans %}Index of proposed improvements to Python{% endtrans %}</span></li>
       <li class="biglink"><a class="biglink" href="https://typing.python.org">{% trans %}Static Typing with Python{% endtrans %}</a><br>
          <span class="linkdescr">{% trans %}Information and guides about Python type safety{% endtrans %}</span></li>
     </ul>

Doc/tools/templates/indexsidebar.html

@@ -6,12 +6,3 @@ <h3>{% trans %}Docs by version{% endtrans %}</h3>
   {% include "_docs_by_version.html" without context %}
   <li><a href="https://www.python.org/doc/versions/">{% trans %}All versions{% endtrans %}</a></li>
 </ul>
-<h3>{% trans %}Other resources{% endtrans %}</h3>
-<ul>
-  {# XXX: many of these should probably be merged in the main docs #}
-  <li><a href="https://peps.python.org/">{% trans %}PEP index{% endtrans %}</a></li>
-  <li><a href="https://wiki.python.org/moin/BeginnersGuide">{% trans %}Beginner's guide{% endtrans %}</a></li>
-  <li><a href="https://wiki.python.org/moin/PythonBooks">{% trans %}Book list{% endtrans %}</a></li>
-  <li><a href="https://www.python.org/doc/av/">{% trans %}Audio/visual talks{% endtrans %}</a></li>
-  <li><a href="https://devguide.python.org/">{% trans %}Python developer’s guide{% endtrans %}</a></li>
-</ul>

Doc/whatsnew/3.16.rst

@@ -872,3 +872,12 @@ Deprecated C APIs
 
 Removed C APIs
 --------------
+
+* The :c:var:`!PyUnstable_ExecutableKinds` array, as well as the macros
+  :c:macro:`!PyUnstable_EXECUTABLE_KIND_SKIP`,
+  :c:macro:`!PyUnstable_EXECUTABLE_KIND_PY_FUNCTION`,
+  :c:macro:`!PyUnstable_EXECUTABLE_KIND_BUILTIN_FUNCTION`,
+  :c:macro:`!PyUnstable_EXECUTABLE_KIND_METHOD_DESCRIPTOR` and
+  :c:macro:`!PyUnstable_EXECUTABLE_KINDS`, were removed.
+
+  (Contributed by Peters Bierma and Viktorin in :gh:`152105`.)

Include/cpython/pyframe.h

@@ -35,11 +35,3 @@ PyAPI_FUNC(int) PyUnstable_InterpreterFrame_GetLasti(struct _PyInterpreterFrame
 /* Returns the currently executing line number, or -1 if there is no line number.
  * Does not raise an exception. */
 PyAPI_FUNC(int) PyUnstable_InterpreterFrame_GetLine(struct _PyInterpreterFrame *frame);
-
-#define PyUnstable_EXECUTABLE_KIND_SKIP 0
-#define PyUnstable_EXECUTABLE_KIND_PY_FUNCTION 1
-#define PyUnstable_EXECUTABLE_KIND_BUILTIN_FUNCTION 3
-#define PyUnstable_EXECUTABLE_KIND_METHOD_DESCRIPTOR 4
-#define PyUnstable_EXECUTABLE_KINDS 5
-
-PyAPI_DATA(const PyTypeObject *) const PyUnstable_ExecutableKinds[PyUnstable_EXECUTABLE_KINDS+1];

Lib/_pydecimal.py

@@ -1824,9 +1824,10 @@ def __round__(self, n=None):
         Decimal('123.46')
         >>> round(Decimal('123.456'), -2)
         Decimal('1E+2')
-        >>> round(Decimal('-Infinity'), 37)
+        >>> with localcontext(ExtendedContext):
+        ...     round(Decimal('-Infinity'), 37)
+        ...     round(Decimal('sNaN123'), 0)
         Decimal('NaN')
-        >>> round(Decimal('sNaN123'), 0)
         Decimal('NaN123')
 
         """

Lib/test/clinic.test.c

@@ -5769,6 +5769,56 @@ Test___init___impl(TestObj *self, PyObject *a, int group_right_1,
 /*[clinic end generated code: output=2bbb8ea60e8f57a6 input=10f5d0f1e8e466ef]*/
 
 
+/*[clinic input]
+only_optional_group
+    [
+    a: object
+    ]
+    /
+The only parameter is in an optional group.
+[clinic start generated code]*/
+
+PyDoc_STRVAR(only_optional_group__doc__,
+"only_optional_group([a])\n"
+"The only parameter is in an optional group.");
+
+#define ONLY_OPTIONAL_GROUP_METHODDEF    \
+    {"only_optional_group", (PyCFunction)only_optional_group, METH_VARARGS, only_optional_group__doc__},
+
+static PyObject *
+only_optional_group_impl(PyObject *module, int group_right_1, PyObject *a);
+
+static PyObject *
+only_optional_group(PyObject *module, PyObject *args)
+{
+    PyObject *return_value = NULL;
+    int group_right_1 = 0;
+    PyObject *a = NULL;
+
+    switch (PyTuple_GET_SIZE(args)) {
+        case 0:
+            break;
+        case 1:
+            if (!PyArg_ParseTuple(args, "O:only_optional_group", &a)) {
+                goto exit;
+            }
+            group_right_1 = 1;
+            break;
+        default:
+            PyErr_SetString(PyExc_TypeError, "only_optional_group requires 0 to 1 arguments");
+            goto exit;
+    }
+    return_value = only_optional_group_impl(module, group_right_1, a);
+
+exit:
+    return return_value;
+}
+
+static PyObject *
+only_optional_group_impl(PyObject *module, int group_right_1, PyObject *a)
+/*[clinic end generated code: output=e7546b9441793d7d input=426c64055af7bcab]*/
+
+
 /*[clinic input]
 group_and_optional_parameter
     [

Lib/test/support/__init__.py

@@ -1293,6 +1293,7 @@ def bigmemtest(size, memuse, dry_run=True):
     test doesn't support dummy runs when -M is not specified.
     """
     def decorator(f):
+        @functools.wraps(f)
         def wrapper(self):
             size = wrapper.size
             memuse = wrapper.memuse
@@ -1345,6 +1346,7 @@ def internal(*args, **kwargs):
 
 def bigaddrspacetest(f):
     """Decorator for tests that fill the address space."""
+    @functools.wraps(f)
     def wrapper(self):
         if max_memuse < MAX_Py_ssize_t:
             if MAX_Py_ssize_t >= 2**63 - 1 and max_memuse >= 2**31:
@@ -1450,6 +1452,7 @@ def no_rerun(reason):
     def deco(func):
         assert not isinstance(func, type), func
         _has_run = False
+        @functools.wraps(func)
         def wrapper(self):
             nonlocal _has_run
             if _has_run: