diff options
| -rw-r--r-- | Doc/howto/annotations.rst | 6 | ||||
| -rw-r--r-- | Doc/library/typing.rst | 4 | ||||
| -rw-r--r-- | Lib/test/test_grammar.py | 22 |
3 files changed, 32 insertions, 0 deletions
diff --git a/Doc/howto/annotations.rst b/Doc/howto/annotations.rst index 2bc2f2d..4720690 100644 --- a/Doc/howto/annotations.rst +++ b/Doc/howto/annotations.rst @@ -57,6 +57,12 @@ Accessing The Annotations Dict Of An Object In Python 3.10 And Newer newer is to call :func:`getattr` with three arguments, for example ``getattr(o, '__annotations__', None)``. + Before Python 3.10, accessing ``__annotations__`` on a class that + defines no annotations but that has a parent class with + annotations would return the parent's ``__annotations__``. + In Python 3.10 and newer, the child class's annotations + will be an empty dict instead. + Accessing The Annotations Dict Of An Object In Python 3.9 And Older =================================================================== diff --git a/Doc/library/typing.rst b/Doc/library/typing.rst index 356f919..4eed6b4 100644 --- a/Doc/library/typing.rst +++ b/Doc/library/typing.rst @@ -2777,6 +2777,10 @@ Introspection helpers .. versionchanged:: 3.9 Added ``include_extras`` parameter as part of :pep:`593`. + .. versionchanged:: 3.10 + Calling ``get_type_hints()`` on a class no longer returns the annotations + of its base classes. + .. versionchanged:: 3.11 Previously, ``Optional[t]`` was added for function and method annotations if a default value equal to ``None`` was set. diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py index 58f907e..5b94602 100644 --- a/Lib/test/test_grammar.py +++ b/Lib/test/test_grammar.py @@ -415,6 +415,28 @@ class GrammarTests(unittest.TestCase): x: int x.y: list = [] + def test_annotations_inheritance(self): + # Check that annotations are not inherited by derived classes + class A: + attr: int + class B(A): + pass + class C(A): + attr: str + class D: + attr2: int + class E(A, D): + pass + class F(C, A): + pass + self.assertEqual(A.__annotations__, {"attr": int}) + self.assertEqual(B.__annotations__, {}) + self.assertEqual(C.__annotations__, {"attr" : str}) + self.assertEqual(D.__annotations__, {"attr2" : int}) + self.assertEqual(E.__annotations__, {}) + self.assertEqual(F.__annotations__, {}) + + def test_var_annot_metaclass_semantics(self): class CMeta(type): @classmethod |