From 6038447d99663b0434a4f2c545c0543e9a81fdc3 Mon Sep 17 00:00:00 2001 From: Jelle Zijlstra Date: Wed, 17 Sep 2025 02:22:16 -0700 Subject: [PATCH] [3.14] gh-137226: Fix get_type_hints() on generic TypedDict with stringified annotations (GH-138953) (#138989) --- Lib/test/test_typing.py | 17 ++++++++-- Lib/typing.py | 32 +++++++++++++------ ...-09-15-13-09-19.gh-issue-137226.HH3_ik.rst | 2 ++ 3 files changed, 39 insertions(+), 12 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2025-09-15-13-09-19.gh-issue-137226.HH3_ik.rst diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py index 889deddc56cd..f19044bbcdee 100644 --- a/Lib/test/test_typing.py +++ b/Lib/test/test_typing.py @@ -7132,6 +7132,19 @@ class GetTypeHintsTests(BaseTestCase): right_hints = get_type_hints(t.add_right, globals(), locals()) self.assertEqual(right_hints['node'], Node[T]) + def test_stringified_typeddict(self): + ns = run_code( + """ + from __future__ import annotations + from typing import TypedDict + class TD[UniqueT](TypedDict): + a: UniqueT + """ + ) + TD = ns['TD'] + self.assertEqual(TD.__annotations__, {'a': EqualToForwardRef('UniqueT', owner=TD, module=TD.__module__)}) + self.assertEqual(get_type_hints(TD), {'a': TD.__type_params__[0]}) + class GetUtilitiesTestCase(TestCase): def test_get_origin(self): @@ -8678,8 +8691,8 @@ class TypedDictTests(BaseTestCase): child = _make_td( child_future, "Child", {"child": "int"}, "Base", {"Base": base} ) - base_anno = ForwardRef("int", module="builtins") if base_future else int - child_anno = ForwardRef("int", module="builtins") if child_future else int + base_anno = ForwardRef("int", module="builtins", owner=base) if base_future else int + child_anno = ForwardRef("int", module="builtins", owner=child) if child_future else int self.assertEqual(base.__annotations__, {'base': base_anno}) self.assertEqual( child.__annotations__, {'child': child_anno, 'base': base_anno} diff --git a/Lib/typing.py b/Lib/typing.py index da5e0b565340..dbc8734418d9 100644 --- a/Lib/typing.py +++ b/Lib/typing.py @@ -172,16 +172,16 @@ class _LazyAnnotationLib: _lazy_annotationlib = _LazyAnnotationLib() -def _type_convert(arg, module=None, *, allow_special_forms=False): +def _type_convert(arg, module=None, *, allow_special_forms=False, owner=None): """For converting None to type(None), and strings to ForwardRef.""" if arg is None: return type(None) if isinstance(arg, str): - return _make_forward_ref(arg, module=module, is_class=allow_special_forms) + return _make_forward_ref(arg, module=module, is_class=allow_special_forms, owner=owner) return arg -def _type_check(arg, msg, is_argument=True, module=None, *, allow_special_forms=False): +def _type_check(arg, msg, is_argument=True, module=None, *, allow_special_forms=False, owner=None): """Check that the argument is a type, and return it (internal helper). As a special case, accept None and return type(None) instead. Also wrap strings @@ -199,7 +199,7 @@ 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, allow_special_forms=allow_special_forms) + arg = _type_convert(arg, module=module, allow_special_forms=allow_special_forms, owner=owner) if (isinstance(arg, _GenericAlias) and arg.__origin__ in invalid_generic_forms): raise TypeError(f"{arg} is not valid as type argument") @@ -431,7 +431,7 @@ _sentinel = _Sentinel() def _eval_type(t, globalns, localns, type_params=_sentinel, *, recursive_guard=frozenset(), - format=None, owner=None, parent_fwdref=None): + format=None, owner=None, parent_fwdref=None, prefer_fwd_module=False): """Evaluate all forward references in the given type t. For use of globalns and localns see the docstring for get_type_hints(). @@ -444,8 +444,20 @@ def _eval_type(t, globalns, localns, type_params=_sentinel, *, recursive_guard=f if isinstance(t, _lazy_annotationlib.ForwardRef): # If the forward_ref has __forward_module__ set, evaluate() infers the globals # from the module, and it will probably pick better than the globals we have here. - if t.__forward_module__ is not None: + # We do this only for calls from get_type_hints() (which opts in through the + # prefer_fwd_module flag), so that the default behavior remains more straightforward. + if prefer_fwd_module and t.__forward_module__ is not None: globalns = None + # If there are type params on the owner, we need to add them back, because + # annotationlib won't. + if owner_type_params := getattr(owner, "__type_params__", None): + globalns = getattr( + sys.modules.get(t.__forward_module__, None), "__dict__", None + ) + if globalns is not None: + globalns = dict(globalns) + for type_param in owner_type_params: + globalns[type_param.__name__] = type_param return evaluate_forward_ref(t, globals=globalns, locals=localns, type_params=type_params, owner=owner, _recursive_guard=recursive_guard, format=format) @@ -466,7 +478,7 @@ def _eval_type(t, globalns, localns, type_params=_sentinel, *, recursive_guard=f ev_args = tuple( _eval_type( a, globalns, localns, type_params, recursive_guard=recursive_guard, - format=format, owner=owner, + format=format, owner=owner, prefer_fwd_module=prefer_fwd_module, ) for a in t.__args__ ) @@ -2363,7 +2375,7 @@ def get_type_hints(obj, globalns=None, localns=None, include_extras=False, if isinstance(value, str): value = _make_forward_ref(value, is_argument=False, is_class=True) value = _eval_type(value, base_globals, base_locals, (), - format=format, owner=obj) + format=format, owner=obj, prefer_fwd_module=True) if value is None: value = type(None) hints[name] = value @@ -2408,7 +2420,7 @@ def get_type_hints(obj, globalns=None, localns=None, include_extras=False, is_argument=not isinstance(obj, types.ModuleType), is_class=False, ) - value = _eval_type(value, globalns, localns, (), format=format, owner=obj) + value = _eval_type(value, globalns, localns, (), format=format, owner=obj, prefer_fwd_module=True) if value is None: value = type(None) hints[name] = value @@ -3147,7 +3159,7 @@ class _TypedDictMeta(type): own_annotations = {} msg = "TypedDict('Name', {f0: t0, f1: t1, ...}); each t must be a type" own_checked_annotations = { - n: _type_check(tp, msg, module=tp_dict.__module__) + n: _type_check(tp, msg, owner=tp_dict, module=tp_dict.__module__) for n, tp in own_annotations.items() } required_keys = set() diff --git a/Misc/NEWS.d/next/Library/2025-09-15-13-09-19.gh-issue-137226.HH3_ik.rst b/Misc/NEWS.d/next/Library/2025-09-15-13-09-19.gh-issue-137226.HH3_ik.rst new file mode 100644 index 000000000000..38683c845dec --- /dev/null +++ b/Misc/NEWS.d/next/Library/2025-09-15-13-09-19.gh-issue-137226.HH3_ik.rst @@ -0,0 +1,2 @@ +Fix :func:`typing.get_type_hints` calls on generic :class:`typing.TypedDict` +classes defined with string annotations. -- 2.47.3