https://github.com/python/cpython/commit/7e652f402f84b412ec46cec42cb103f489a0087e
commit: 7e652f402f84b412ec46cec42cb103f489a0087e
branch: main
author: David Ellis <[email protected]>
committer: JelleZijlstra <[email protected]>
date: 2025-09-06T07:39:49Z
summary:
gh-137706: make typing._is_unpacked_typevartuple check for `True` instead of
truthy (#137712)
files:
A Misc/NEWS.d/next/Library/2025-09-05-21-10-24.gh-issue-137706.0EztiJ.rst
M Lib/test/test_typing.py
M Lib/typing.py
diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
index 6317d4657619f0..0fc5415c390145 100644
--- a/Lib/test/test_typing.py
+++ b/Lib/test/test_typing.py
@@ -9788,6 +9788,19 @@ class B(str): ...
self.assertIs(type(field_c2.__metadata__[0]), float)
self.assertIs(type(field_c3.__metadata__[0]), bool)
+ def test_forwardref_partial_evaluation(self):
+ # Test that Annotated partially evaluates if it contains a ForwardRef
+ # See: https://github.com/python/cpython/issues/137706
+ def f(x: Annotated[undefined, '']): pass
+
+ ann = annotationlib.get_annotations(f,
format=annotationlib.Format.FORWARDREF)
+
+ # Test that the attributes are retrievable from the partially
evaluated annotation
+ x_ann = ann['x']
+ self.assertIs(get_origin(x_ann), Annotated)
+ self.assertEqual(x_ann.__origin__, EqualToForwardRef('undefined',
owner=f))
+ self.assertEqual(x_ann.__metadata__, ('',))
+
class TypeAliasTests(BaseTestCase):
def test_canonical_usage_with_variable_annotation(self):
diff --git a/Lib/typing.py b/Lib/typing.py
index ea25e3832bd0be..babe3c44d9dc55 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -1027,8 +1027,10 @@ def evaluate_forward_ref(
def _is_unpacked_typevartuple(x: Any) -> bool:
+ # Need to check 'is True' here
+ # See: https://github.com/python/cpython/issues/137706
return ((not isinstance(x, type)) and
- getattr(x, '__typing_is_unpacked_typevartuple__', False))
+ getattr(x, '__typing_is_unpacked_typevartuple__', False) is True)
def _is_typevar_like(x: Any) -> bool:
diff --git
a/Misc/NEWS.d/next/Library/2025-09-05-21-10-24.gh-issue-137706.0EztiJ.rst
b/Misc/NEWS.d/next/Library/2025-09-05-21-10-24.gh-issue-137706.0EztiJ.rst
new file mode 100644
index 00000000000000..9eed50ec20a8f6
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-09-05-21-10-24.gh-issue-137706.0EztiJ.rst
@@ -0,0 +1 @@
+Fix the partial evaluation of annotations that use ``typing.Annotated[T, x]``
where ``T`` is a forward reference.
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