Add deprecation flag and warning

python · JelleZijlstra · Feb 17, 2022 · Feb 4, 2022 · Feb 7, 2022 · Feb 8, 2022
commit f3588ac8ba55ec7d629eac36b7f504d2ba9d3c3b
@@ -1388,10 +1388,15 @@ These are not used in annotations. They are building blocks for declaring types.
    ``Point2D.__total__``, ``Point2D.__required_keys__``, and
    ``Point2D.__optional_keys__``.
    To allow using this feature with older versions of Python that do not
-   support :pep:`526`, ``TypedDict`` supports an additional equivalent
-   syntactic form::
+   support :pep:`526`, ``TypedDict`` supports two additional equivalent
+   syntactic forms::
 
       Point2D = TypedDict('Point2D', {'x': int, 'y': int, 'label': str})
+      Point2D = TypedDict('Point2D', x=int, y=int, label=str)
+
+   .. deprecated-removed:: 3.11 3.13
+      The keyword arguments syntax is deprecated in 3.11 and will be removed
+      in 3.13. Currently it might not be supported by typecheckers like ``mypy``.
 
    By default, all keys must be present in a ``TypedDict``. It is possible to
    override this by specifying totality.

@@ -4299,6 +4299,34 @@ def test_basics_functional_syntax(self):
         self.assertEqual(Emp.__annotations__, {'name': str, 'id': int})
         self.assertEqual(Emp.__total__, True)
 
+    def test_basics_keywords_syntax(self):
+        with self.assertWarns(DeprecationWarning):
+            Emp = TypedDict('Emp', name=str, id=int)
+            self.assertIsSubclass(Emp, dict)
+            self.assertIsSubclass(Emp, typing.MutableMapping)
+            self.assertNotIsSubclass(Emp, collections.abc.Sequence)
+            jim = Emp(name='Jim', id=1)
+            self.assertIs(type(jim), dict)
+            self.assertEqual(jim['name'], 'Jim')
+            self.assertEqual(jim['id'], 1)
+            self.assertEqual(Emp.__name__, 'Emp')
+            self.assertEqual(Emp.__module__, __name__)
+            self.assertEqual(Emp.__bases__, (dict,))
+            self.assertEqual(Emp.__annotations__, {'name': str, 'id': int})
+            self.assertEqual(Emp.__total__, True)
+
+    def test_typeddict_special_keyword_names(self):
+        TD = TypedDict("TD", {'cls': type, 'self': object, 'typename': str, '_typename': int, 'fields': list, '_fields': dict})
+        self.assertEqual(TD.__name__, 'TD')
+        self.assertEqual(TD.__annotations__, {'cls': type, 'self': object, 'typename': str, '_typename': int, 'fields': list, '_fields': dict})
+        a = TD(cls=str, self=42, typename='foo', _typename=53, fields=[('bar', tuple)], _fields={'baz', set})
+        self.assertEqual(a['cls'], str)
+        self.assertEqual(a['self'], 42)
+        self.assertEqual(a['typename'], 'foo')
+        self.assertEqual(a['_typename'], 53)
+        self.assertEqual(a['fields'], [('bar', tuple)])
+        self.assertEqual(a['_fields'], {'baz', set})
+
     def test_typeddict_create_errors(self):
         with self.assertRaises(TypeError):
             TypedDict.__new__()

@@ -2378,7 +2378,7 @@ def __subclasscheck__(cls, other):
     __instancecheck__ = __subclasscheck__
 
 
-def TypedDict(typename, fields=None, /, *, total=True):
+def TypedDict(typename, fields=None, /, *, total=True, **kwargs):
     """A simple typed namespace. At runtime it is equivalent to a plain dict.
 
     TypedDict creates a dictionary type that expects all of its
@@ -2419,6 +2419,18 @@ class body be required.
     The class syntax is only supported in Python 3.6+, while two other
     syntax forms work for Python 2.7 and 3.2+
     """
+    if fields is None:
+        fields = kwargs
+    elif kwargs:
+        raise TypeError("TypedDict takes either a dict or keyword arguments,"
+                        " but not both")
+    if kwargs:
+        warnings.warn(
+            "The kwargs-based syntax for TypedDict definition is deprecated "
+            " in Python 3.11 and will be removed in Python 3.13.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
 
     ns = {'__annotations__': dict(fields)}
     module = _caller()