gh-85795: Add support for super() in NamedTuple subclasses

Doc/library/typing.rst

@@ -2389,6 +2389,11 @@ types.
       disallowed in Python 3.15. To create a NamedTuple class with 0 fields,
       use ``class NT(NamedTuple): pass`` or ``NT = NamedTuple("NT", [])``.
 
+   .. versionchanged:: next
+      Added support for calls to :func:`super` inside user-defined methods
+      of ``NamedTuple`` subclasses to reuse functionality from built-in classes
+      :class:`tuple` and :class:`object`.
+
 .. class:: NewType(name, tp)
 
    Helper class to create low-overhead :ref:`distinct types <distinct>`.

Lib/collections/__init__.py

@@ -358,30 +358,10 @@ def __ror__(self, other):
 except ImportError:
     _tuplegetter = lambda index, doc: property(_itemgetter(index), doc=doc)
 
-def namedtuple(typename, field_names, *, rename=False, defaults=None, module=None):
-    """Returns a new subclass of tuple with named fields.
-
-    >>> Point = namedtuple('Point', ['x', 'y'])
-    >>> Point.__doc__                   # docstring for the new class
-    'Point(x, y)'
-    >>> p = Point(11, y=22)             # instantiate with positional args or keywords
-    >>> p[0] + p[1]                     # indexable like a plain tuple
-    33
-    >>> x, y = p                        # unpack like a regular tuple
-    >>> x, y
-    (11, 22)
-    >>> p.x + p.y                       # fields also accessible by name
-    33
-    >>> d = p._asdict()                 # convert to a dictionary
-    >>> d['x']
-    11
-    >>> Point(**d)                      # convert from a dictionary
-    Point(x=11, y=22)
-    >>> p._replace(x=100)               # _replace() is like str.replace() but targets named fields
-    Point(x=100, y=22)
-
-    """
+_nmtuple_classcell_sentinel = object()
 
+def _namedtuple(typename, field_names, *, rename=False, defaults=None, module=None,
+                classcell=_nmtuple_classcell_sentinel, stack_offset=1):
     # Validate the field names.  At the user's option, either generate an error
     # message or automatically replace the field name with a valid name.
     if isinstance(field_names, str):
@@ -508,6 +488,12 @@ def __getnewargs__(self):
         '__getnewargs__': __getnewargs__,
         '__match_args__': field_names,
     }
+
+    # gh-85795: `super()` calls inside `typing.NamedTuple` methods will not
+    # work unless `__classcell__` is propagated by `collections._namedtuple`
+    if classcell is not _nmtuple_classcell_sentinel:
+        class_namespace["__classcell__"] = classcell
+
     for index, name in enumerate(field_names):
         doc = _sys.intern(f'Alias for field number {index}')
         class_namespace[name] = _tuplegetter(index, doc)
@@ -521,17 +507,42 @@ def __getnewargs__(self):
     # specified a particular module.
     if module is None:
         try:
-            module = _sys._getframemodulename(1) or '__main__'
+            module = _sys._getframemodulename(stack_offset) or '__main__'
         except AttributeError:
             try:
-                module = _sys._getframe(1).f_globals.get('__name__', '__main__')
+                module = _sys._getframe(stack_offset).f_globals.get('__name__', '__main__')
             except (AttributeError, ValueError):
                 pass
     if module is not None:
         result.__module__ = module
 
     return result
 
+def namedtuple(typename, field_names, *, rename=False, defaults=None, module=None):
+    """Returns a new subclass of tuple with named fields.
+
+    >>> Point = namedtuple('Point', ['x', 'y'])
+    >>> Point.__doc__                   # docstring for the new class
+    'Point(x, y)'
+    >>> p = Point(11, y=22)             # instantiate with positional args or keywords
+    >>> p[0] + p[1]                     # indexable like a plain tuple
+    33
+    >>> x, y = p                        # unpack like a regular tuple
+    >>> x, y
+    (11, 22)
+    >>> p.x + p.y                       # fields also accessible by name
+    33
+    >>> d = p._asdict()                 # convert to a dictionary
+    >>> d['x']
+    11
+    >>> Point(**d)                      # convert from a dictionary
+    Point(x=11, y=22)
+    >>> p._replace(x=100)               # _replace() is like str.replace() but targets named fields
+    Point(x=100, y=22)
+
+    """
+    return _namedtuple(typename, field_names, rename=rename, defaults=defaults, module=module,
+                       stack_offset=2)
 
 ########################################################################
 ###  Counter

Lib/test/test_typing.py

@@ -8135,6 +8135,38 @@ class Group(NamedTuple):
         self.assertIs(type(a), Group)
         self.assertEqual(a, (1, [2]))
 
+    def test_super_and_dunder_class_work(self):
+        # See #85795: __class__ not set defining 'X' as <class '__main__.X'>
+
+        class Pointer(NamedTuple):
+            address: int
+            target_type = "int"
+
+            @property
+            def typename(self):
+                return __class__.target_type
+
+            def count(self, item):
+                if item == 0:
+                    return -1
+                return super().count(self.address)
+
+        ptr = Pointer(0xdeadbeef)
+        self.assertEqual(ptr.typename, "int")
+        self.assertEqual(ptr.count(0), -1)
+        self.assertEqual(ptr.count(0xdeadbeef), 1)
+
+    @cpython_only
+    def test_classcell_not_leaked(self):
+        # __classcell__ should never leak into end classes
+
+        class Spam(NamedTuple):
+            lambda: super()
+            lambda: __class__
+
+        with self.assertRaises(AttributeError):
+            Spam.__classcell__
+
     def test_namedtuple_keyword_usage(self):
         with self.assertWarnsRegex(
             DeprecationWarning,

Lib/typing.py

@@ -2929,9 +2929,10 @@ def __round__(self, ndigits: int = 0) -> T:
         pass
 
 
-def _make_nmtuple(name, fields, annotate_func, module, defaults = ()):
-    nm_tpl = collections.namedtuple(name, fields,
-                                    defaults=defaults, module=module)
+def _make_nmtuple(name, fields, annotate_func, module, defaults = (),
+                  classcell=collections._nmtuple_classcell_sentinel):
+    nm_tpl = collections._namedtuple(name, fields, defaults=defaults,
+                                     module=module, classcell=classcell)
     nm_tpl.__annotate__ = nm_tpl.__new__.__annotate__ = annotate_func
     return nm_tpl
 
@@ -2999,8 +3000,8 @@ def annotate(format):
                                 f"{'s' if len(default_names) > 1 else ''} "
                                 f"{', '.join(default_names)}")
         nm_tpl = _make_nmtuple(typename, field_names, annotate,
-                               defaults=[ns[n] for n in default_names],
-                               module=ns['__module__'])
+                               defaults=[ns[n] for n in default_names], module=ns['__module__'],
+                               classcell=ns.pop('__classcell__', collections._nmtuple_classcell_sentinel))
         nm_tpl.__bases__ = bases
         if Generic in bases:
             class_getitem = _generic_class_getitem

Misc/NEWS.d/next/Library/2025-01-27-12-55-40.gh-issue-85795.fnGbGS.rst

@@ -0,0 +1,2 @@
+Added support for :func:`super` calls in user-defined
+:class:`~typing.NamedTuple` methods. Contributed by Bartosz Sławecki.