gh-116241: Add support of multiple inheritance with typing.NamedTuple

Doc/library/typing.rst

@@ -2120,6 +2120,9 @@ types.
       disallowed in Python 3.15. To create a NamedTuple class with 0 fields,
       use ``class NT(NamedTuple): pass`` or ``NT = NamedTuple("NT", [])``.
 
+   .. versionchanged:: 3.13
+      Added support of multiple inheritence.
+
 .. class:: NewType(name, tp)
 
    Helper class to create low-overhead :ref:`distinct types <distinct>`.

Doc/whatsnew/3.13.rst

@@ -582,6 +582,9 @@ typing
   check whether a class is a :class:`typing.Protocol`. (Contributed by Jelle Zijlstra in
   :gh:`104873`.)
 
+* Add support of multiple inheritance with :class:`~typing.NamedTuple`.
+  (Contributed by Serhiy Storchaka in :gh:`116241`.)
+
 unicodedata
 -----------
 

Lib/test/test_typing.py

@@ -7457,7 +7457,40 @@ def _source(self):
 
     def test_multiple_inheritance(self):
         class A:
-            pass
+            @property
+            def x(self):
+                return 4
+            @property
+            def y(self):
+                return 5
+            def __len__(self):
+                return 10
+
+        class X(NamedTuple, A):
+            x: int
+        self.assertEqual(X.__bases__, (tuple, A))
+        self.assertEqual(X.__orig_bases__, (NamedTuple, A))
+        self.assertEqual(X.__mro__, (X, tuple, A, object))
+
+        a = X(3)
+        self.assertEqual(a.x, 3)
+        self.assertEqual(a.y, 5)
+        self.assertEqual(len(a), 1)
+
+        class Y(A, NamedTuple):
+            x: int
+        self.assertEqual(Y.__bases__, (A, tuple))
+        self.assertEqual(Y.__orig_bases__, (A, NamedTuple))
+        self.assertEqual(Y.__mro__, (Y, A, tuple, object))
+
+        a = Y(3)
+        self.assertEqual(a.x, 3)
+        self.assertEqual(a.y, 5)
+        self.assertEqual(len(a), 10)
+
+    def test_multiple_inheritance_errors(self):
+        class A(NamedTuple):
+            x: int
         with self.assertRaises(TypeError):
             class X(NamedTuple, A):
                 x: int

Lib/typing.py

@@ -2794,10 +2794,6 @@ def _make_nmtuple(name, types, module, defaults = ()):
 class NamedTupleMeta(type):
     def __new__(cls, typename, bases, ns):
         assert _NamedTuple in bases
-        for base in bases:
-            if base is not _NamedTuple and base is not Generic:
-                raise TypeError(
-                    'can only inherit from a NamedTuple type and Generic')
         bases = tuple(tuple if base is _NamedTuple else base for base in bases)
         types = ns.get('__annotations__', {})
         default_names = []

Misc/NEWS.d/next/Library/2022-04-28-18-45-58.gh-issue-116241.hu9kRk.rst

@@ -0,0 +1 @@
+Add support of multiple inheritance with :class:`typing.NamedTuple`.