[New-bugs-announce] [issue41872] get_type_hints fails to resolve forward references in nested function

[Chris Withers]

New submission from Chris Withers <chris at withers.org>:

Reproducer:

    def test_forward_type_references(self):
        def foo(a: 'Foo') -> 'Bar': pass

        class Foo: pass
        class Bar: pass

        get_type_hints(foo)


The above gives the following exception, rather than resolving the type:

/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/typing.py:1001: in get_type_hints
    value = _eval_type(value, globalns, localns)
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/typing.py:260: in _eval_type
    return t._evaluate(globalns, localns)
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/typing.py:464: in _evaluate
    eval(self.__forward_code__, globalns, localns),
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

>   ???
E   NameError: name 'Foo' is not defined

----------
components: Library (Lib)
messages: 377569
nosy: cjw296
priority: normal
severity: normal
status: open
title: get_type_hints fails to resolve forward references in nested function
type: behavior
versions: Python 3.10, Python 3.7, Python 3.8, Python 3.9

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue41872>
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