Mention Python >= 3.9.2 as an alternative to `typing_extensions.Typed…

…Dict` (#3374)

* Mention python >= 3.9.2 as an alternative to `typing_extensions.TypedDict`

* Narrow the upper version for `LegacyTypedDict`: 3.9 -> 3.9.2

* Add an entry to `changes`

* Update pydantic/annotated_types.py

Co-authored-by: Samuel Colvin <samcolvin@gmail.com>

* Update `TypedDict` exception message in the test suite

* linting

Co-authored-by: Samuel Colvin <samcolvin@gmail.com>
Co-authored-by: Samuel Colvin <s@muelcolvin.com>

changes/3374-BvB93.md

@@ -0,0 +1 @@
+Mention Python >= 3.9.2 as an alternative to `typing_extensions.TypedDict`.

pydantic/annotated_types.py

@@ -22,7 +22,7 @@ def create_model_from_typeddict(
     # Best case scenario: with python 3.9+ or when `TypedDict` is imported from `typing_extensions`
     if not hasattr(typeddict_cls, '__required_keys__'):
         raise TypeError(
-            'You should use `typing_extensions.TypedDict` instead of `typing.TypedDict`. '
+            'You should use `typing_extensions.TypedDict` instead of `typing.TypedDict` with Python < 3.9.2. '
             'Without it, there is no way to differentiate required and optional fields when subclassed.'
         )
 

tests/test_annotated_types.py

@@ -13,7 +13,7 @@
 
 from pydantic import BaseModel, PositiveInt, ValidationError
 
-if sys.version_info < (3, 9):
+if sys.version_info < (3, 9, 2):
     try:
         from typing import TypedDict as LegacyTypedDict
     except ImportError:
@@ -221,7 +221,10 @@ class OptionalUser(LegacyTypedDict, total=False):
     class User(OptionalUser):
         id: int
 
-    with pytest.raises(TypeError, match='^You should use `typing_extensions.TypedDict` instead of `typing.TypedDict`'):
+    with pytest.raises(
+        TypeError,
+        match='^You should use `typing_extensions.TypedDict` instead of `typing.TypedDict` with Python < 3.9.2.',
+    ):
 
         class Model(BaseModel):
             user: User