Guido van Rossum <gu...@python.org> added the comment:
Ah, I see the issue. I stepped through get_type_hints() using pdb, and it does have a special case for when it encounters a string: it wraps it in a ForwardRef and proceeds from there: https://github.com/python/cpython/blob/cef0a5458f254c2f8536b928dee25862ca90ffa6/Lib/typing.py#L1806-L1807 But list['N'] isn't a string, so it doesn't trigger this case. If you were to use "list[N]" instead, it works: >>> from typing import get_type_hints >>> class N: ... c: "list[N]" ... >>> get_type_hints(N) {'c': list[__main__.N]} >>> But I suppose you have a reason you (or your users) don't want to do that. We could probably add a special case where it checks for types.GenericAlias and goes through __args__, replacing strings by ForwardRefs. But would that be enough? The algorithm would have to recursively dive into __args__ to see if there's a string hidden deep inside, e.g. list[tuple[int, list["N"]]]. And what if the user writes something hybrid, like List[list["N"]]? What other cases would we need to cover? And can we sell this as a bugfix for 3.10, or will this be a new feature in 3.11? How will it interact with from __future__ import annotations? ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue41370> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
