get_type_hints() fails on TypedDict inheriting from a generic TypedDict under PEP 563
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Description
Bug report
Bug description:
This fails:
from __future__ import annotations
import typing
class TD1[T](typing.TypedDict):
a: T
class TD2(TD1):
pass
print(typing.get_type_hints(TD2))
$ uv run --python=3.13 sample3.py
Traceback (most recent call last):
File "/Users/jelle/py/cpython/sample3.py", line 9, in <module>
print(typing.get_type_hints(TD2))
~~~~~~~~~~~~~~~~~~~~~^^^^^
File "/opt/homebrew/Cellar/python@3.13/3.13.7/Frameworks/Python.framework/Versions/3.13/lib/python3.13/typing.py", line 2461, in get_type_hints
value = _eval_type(value, base_globals, base_locals, base.__type_params__)
File "/opt/homebrew/Cellar/python@3.13/3.13.7/Frameworks/Python.framework/Versions/3.13/lib/python3.13/typing.py", line 474, in _eval_type
return t._evaluate(globalns, localns, type_params, recursive_guard=recursive_guard)
~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/opt/homebrew/Cellar/python@3.13/3.13.7/Frameworks/Python.framework/Versions/3.13/lib/python3.13/typing.py", line 1081, in _evaluate
eval(self.__forward_code__, globalns, localns),
~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "<string>", line 1, in <module>
NameError: name 'T' is not defined
Also reproduces on 3.12 and on the latest RC of 3.14.
(Got here while investigating https://github.com/python/cpython/issues/137226#issuecomment-3275500742, but since this variant is a longstanding bug we don't need to fix it for 3.14.0. I want to record and eventually fix it though.)
CPython versions tested on:
CPython main branch, 3.15, 3.14, 3.13, 3.12
Operating systems tested on:
macOS
Linked PRs
- gh-150762
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Run the provided TypedDict reproducer on an affected CPython version, then inspect typing.py at get_type_hints() and the _eval_type() call shown in the traceback. Compare the behavior and tests associated with linked PR gh-150762; done means the example resolves its inherited generic annotation without raising NameError.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- backend
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100