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typing.get_type_hints fails when passed a class with PEP 695 type parameters and PEP 563 is enabled #114053
Description
Bug report
Bug description:
from __future__ import annotations
import typing
class Test[M]:
attr: M
print(typing.get_type_hints(Test))This fails with a NameError:
$ poetry run python3 pep_695_get_type_hints.py
Traceback (most recent call last):
File "/home/mjog/pep_695_get_type_hints.py", line 8, in <module>
print(typing.get_type_hints(Test))
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.12/typing.py", line 2197, in get_type_hints
value = _eval_type(value, base_globals, base_locals)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.12/typing.py", line 393, in _eval_type
return t._evaluate(globalns, localns, recursive_guard)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.12/typing.py", line 900, in _evaluate
eval(self.__forward_code__, globalns, localns),
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "<string>", line 1, in <module>
NameError: name 'M' is not defined
Although get_type_hints does not work with imported imported type aliases, this is not imported, so I would expect it to work. Further, the documentation for the function indicates using PEP 563 should /help/, but in this case it actually causes an error.
FWIW, removing the PEP 563 import works fine, giving:
{'attr': M}
Python version:
$ poetry run python3 --version
Python 3.12.0
CPython versions tested on:
3.12
Operating systems tested on:
Linux
Linked PRs
- gh-114053: Fix bad interaction of PEP-695, PEP-563 and
get_type_hints#118009 - [3.12] gh-114053: Fix bad interaction of PEP-695, PEP-563 and
get_type_hints(#118009) #118104 - gh-114053: Fix bad interaction of PEP 695, PEP 563 and
inspect.get_annotations#120270 - gh-114053: Fix another edge case involving
get_type_hints, PEP 695 and PEP 563 #120272 - [3.13] gh-114053: Fix bad interaction of PEP 695, PEP 563 and
inspect.get_annotations(GH-120270) #120474 - [3.12] gh-114053: Fix bad interaction of PEP 695, PEP 563 and
inspect.get_annotations(GH-120270) #120475 - [3.13] gh-114053: Fix another edge case involving
get_type_hints, PEP 695 and PEP 563 (GH-120272) #121003 - [3.12] gh-114053: Fix another edge case involving
get_type_hints, PEP 695 and PEP 563 (GH-120272) #121004
Activity
mjog commentedon Jan 14, 2024
[-]typing.get_type_hints fails when passed a class with PEP 695 type parameters and PEP 563 is enabled[/-][+]typing.get_type_hints fails when passed a generic class and PEP 563 is enabled[/+][-]typing.get_type_hints fails when passed a generic class and PEP 563 is enabled[/-][+]typing.get_type_hints fails when passed a class with PEP 695 type parameters and PEP 563 is enabled[/+]mjog commentedon Jan 15, 2024
Sorry, my now-hidden comment above is incorrect - it does work fine with pre-695 generic classes, I just had a typo in the code.
This is only an issue with PEP 695 type parameters in conjunction with PEP 563.
treykeown commentedon Jan 19, 2024
+1, just ran into this as well.
AlexWaygood commentedon Apr 17, 2024
I suppose the problem is probably that
get_type_hintslooks things up in the global scope but doesn't look things up in the new annotation scopes introduced by PEP-695. The old way of defining TypeVars doesn't suffer from this because TypeVars were defined in the global scope; now they aren't.pythongh-114053: Fix bad interaction of PEP-695, PEP-563 and ``get_ty…
gh-114053: Fix bad interaction of PEP-695, PEP-563 and ``get_type_hin…
[3.12] pythongh-114053: Fix bad interaction of PEP-695, PEP-563 and `…
[3.12] gh-114053: Fix bad interaction of PEP-695, PEP-563 and ``get_t…
9 remaining items
pythongh-114053: Fix bad interaction of PEP 695, PEP 563 and `inspect…
[3.12] gh-114053: Fix bad interaction of PEP 695, PEP 563 and `inspec…
[3.13] gh-114053: Fix bad interaction of PEP 695, PEP 563 and `inspec…
gh-114053: Fix another edge case involving `get_type_hints`, PEP 695 …
pythongh-114053: Fix another edge case involving `get_type_hints`, PE…
pythongh-114053: Fix another edge case involving `get_type_hints`, PE…
[3.13] gh-114053: Fix another edge case involving `get_type_hints`, P…
[3.12] gh-114053: Fix another edge case involving `get_type_hints`, P…
pythongh-114053: Fix bad interaction of PEP 695, PEP 563 and `inspect…
pythongh-114053: Fix another edge case involving `get_type_hints`, PE…
pythongh-114053: Fix bad interaction of PEP 695, PEP 563 and `inspect…
pythongh-114053: Fix another edge case involving `get_type_hints`, PE…
pythongh-114053: Fix bad interaction of PEP 695, PEP 563 and `inspect…
pythongh-114053: Fix another edge case involving `get_type_hints`, PE…