diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py index d4068242da6da1..ec286c6e6d68ea 100644 --- a/Lib/test/test_typing.py +++ b/Lib/test/test_typing.py @@ -2788,6 +2788,20 @@ def foo(a: 'Callable[..., T]'): self.assertEqual(get_type_hints(foo, globals(), locals()), {'a': Callable[..., T]}) + def test_special_forms_forward(self): + + class C: + a: Annotated['ClassVar[int]', (3, 5)] = 4 + b: Annotated['Final[int]', "const"] = 4 + + class CF: + b: List['Final[int]'] = 4 + + self.assertEqual(get_type_hints(C, globals())['a'], ClassVar[int]) + self.assertEqual(get_type_hints(C, globals())['b'], Final[int]) + with self.assertRaises(TypeError): + get_type_hints(CF, globals()), + def test_syntax_error(self): with self.assertRaises(SyntaxError): diff --git a/Lib/typing.py b/Lib/typing.py index 705331a9a89a07..80b68fa5db17a0 100644 --- a/Lib/typing.py +++ b/Lib/typing.py @@ -134,12 +134,12 @@ # legitimate imports of those modules. -def _type_convert(arg, module=None): +def _type_convert(arg, module=None, *, allow_special_forms=False): """For converting None to type(None), and strings to ForwardRef.""" if arg is None: return type(None) if isinstance(arg, str): - return ForwardRef(arg, module=module) + return ForwardRef(arg, module=module, is_class=allow_special_forms) return arg @@ -161,7 +161,7 @@ def _type_check(arg, msg, is_argument=True, module=None, *, allow_special_forms= if is_argument: invalid_generic_forms += (Final,) - arg = _type_convert(arg, module=module) + arg = _type_convert(arg, module=module, allow_special_forms=allow_special_forms) if (isinstance(arg, _GenericAlias) and arg.__origin__ in invalid_generic_forms): raise TypeError(f"{arg} is not valid as type argument") diff --git a/Misc/NEWS.d/next/Library/2022-01-26-20-36-30.bpo-46539.23iW1d.rst b/Misc/NEWS.d/next/Library/2022-01-26-20-36-30.bpo-46539.23iW1d.rst new file mode 100644 index 00000000000000..2bdde21b6e58e5 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2022-01-26-20-36-30.bpo-46539.23iW1d.rst @@ -0,0 +1 @@ +In :func:`typing.get_type_hints`, support evaluating stringified ``ClassVar`` and ``Final`` annotations inside ``Annotated``. Patch by Gregory Beauregard.