Maximilian Hils <python-b...@maximilianhils.com> added the comment:
Thank you Ken and Guido for the super quick feedback! > It's not fine if it were to look in the wrong namespace That's a really good point. Here's another terrible example: foo.py: ``` import typing FooData: typing.TypeAlias = "Data" class Data: pass ``` bar.py: ``` import typing import foo BarData: typing.TypeAlias = "Data" def func1(x: foo.FooData, y: BarData): pass class Data: pass print(typing.get_type_hints(func1)) # incorrectly uses bar.Data twice. ``` I don't see how we could distinguish FooData from BarData without static analysis. Changing get_type_hints to not pick the unrelated class with the same name would essentially mean not using func.__globals__, which breaks almost all ForwardRef evaluation. This doesn't seem viable. Potential alternatives: 1. Accept the current state: get_type_hints does not work well with type aliases that use forward references. 2. Fix it at least for cases where a ForwardRef is constructed immediately (typing.List["Foo"], but not "Foo" or list["Foo"]), similar to how it's been done for #41249. I have made a very basic proof-of-concept at https://github.com/mhils/cpython/commit/4adbcf088d2857166b579f7dd2954ff9981fc7db, but it's a mess (see commit comments). 3. Deprecate/discourage use of forward references in type aliases and/or change the syntax for [forward references in] type aliases so that their origin can be tracked. In summary, it seems like there are no really good solutions here. I'm fine if this ends up as a pragmatic wontfix, maybe with a comment added somewhere in the docs or in PEP 613. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue44926> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com