python / python/cpython

`types._GeneratorWrapper` is no longer consistent with `types.GeneratorType`/`types.CoroutineType`

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stdlib type-bug
Dominant language
Python
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Description

Bug report

Bug description:

types.coroutine() uses _GeneratorWrapper as a wrapper for generator iterators in cases where the callable object is not a user-defined function (but is, for example, a generator function compiled via Cython/Nuitka). However, the implementation has not been updated for 11 years and therefore does not provide certain properties, such as:

  • GeneratorType.gi_suspended (Python ≥3.11, python/cpython#30633)
  • CoroutineType.cr_suspended (Python ≥3.11, python/cpython#30633)
  • CoroutineType.cr_origin (Python ≥3.7, python/cpython#5250)

As a result, the objects returned by the new function do not look exactly like types.GeneratorType/types.CoroutineType, which in particular makes them incompatible with the inspect.getgeneratorstate() and inspect.getcoroutinestate() functions:

>>> from inspect import getcoroutinestate, getgeneratorstate
>>> from types import coroutine
>>> def generator_function():
...     return
...     yield  # generator definition
>>> @coroutine
... def coroutine_function():
...     return generator_function()
>>> gencoro = coroutine_function()
>>> getgeneratorstate(gencoro)
Traceback (most recent call last):
AttributeError: '_GeneratorWrapper' object has no attribute 'gi_suspended'
>>> getcoroutinestate(gencoro)
Traceback (most recent call last):
AttributeError: '_GeneratorWrapper' object has no attribute 'cr_suspended'

Interestingly, there was already an attempt to add *_suspended in #133373 (see https://github.com/python/cpython/issues/133372#issuecomment-2849166854), but the PR was closed in favor of removing the TODO comment, and this side issue was apparently overlooked.

Related: cython/cython#7448.

CPython versions tested on:

3.11, 3.12, 3.13, 3.14

Operating systems tested on:

Linux

Linked PRs
  • gh-143609

Contributor guide

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with Lib/types.py lines 255-289, then inspect.getgeneratorstate() and inspect.getcoroutinestate(), which the report identifies as affected entry points. Compare the wrapper's exposed attributes with GeneratorType and CoroutineType; done means both inspect functions work for the wrapped objects and the listed suspension and origin properties are consistent.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
backend
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
28/100

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