Description

skirpichev

opened on Feb 10, 2024

Issue body actions

Bug report

Bug description:

An example:

>>> bytes.maketrans.__module__ is None
True

c.f. pure-python staticmethod:

>>> class Spam:
...     @staticmethod
...     def foo():
...         pass
... 
>>> Spam.foo.__module__
'__main__'

I'm not sure, maybe this should be treated rather as a feature request. Docs says about the attribute value: "The name of the module the function was defined in, or None if unavailable." But clearly, this value is available: the type_add_method() has type argument and we could query value of its __module__ attribute.

Edit: BTW, same happens for class methods, e.g.:

>>> int.from_bytes.__module__ is None
True

Probably this should be fixed as well.

CPython versions tested on:

CPython main branch

Operating systems tested on:

No response

Linked PRs

• gh-115231: fill __module__ for built-in staticmethods #115232

Activity

1. skirpichev

   added

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   on Feb 10, 2024
2. skirpichev

   added a commit that references this issue on Feb 10, 2024

   pythongh-115231: fill __module__ attribute for built-in staticmethods

   9b31877
3. skirpichev

   added a commit that references this issue on Feb 26, 2024

   pythongh-115231: fill __module__ for built-in class/staticmethods

   ff758ab
4. skirpichev

   added a commit that references this issue on Jul 19, 2024

   Revert "pythongh-115231: fill __module__ for built-in class/staticmet…

   38b7d53
5. serhiy-storchaka commented on Nov 2, 2024

   

   serhiy-storchaka

   on Nov 2, 2024

   Member

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   Built-in static and class methods has different types than static and class methods in Python classes. This is not a bug.

   Static and class methods in Python classes started to inherit function attributes only since 3.10 (bpo-43682/gh-87848). cc @vstinner
6. serhiy-storchaka

   added

   type-featureA feature request or enhancementA feature request or enhancement

   3.14bugs and security fixesbugs and security fixes

   and removed

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   on Nov 2, 2024
7. skirpichev commented on Nov 2, 2024

   

   skirpichev

   on Nov 2, 2024

   MemberAuthor

   More actions

   Static and class methods in Python classes started to inherit function attributes only since 3.10

   Hmm, above code snippet works on 3.8+ as well, e.g.:

   Python 3.9.19+ (heads/3.9:3f5d9d12c7, Aug 29 2024, 13:17:09) 
   [GCC 12.2.0] on linux
   Type "help", "copyright", "credits" or "license" for more information.
   >>> class Spam:
   ...     @staticmethod
   ...     def foo():
   ...         pass
   ... 
   >>> Spam.foo.__module__
   '__main__'
   >>> 
8. serhiy-storchaka commented on Nov 2, 2024

   

   serhiy-storchaka

   on Nov 2, 2024

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   Static and class methods in Python classes copy attributes from the wrapped methods. But unbound built-in methods do not have the __module__ attribute, so not copying it is okay. On other hand, bound built-in methods have __module__ equal to None:

   >>> collections.deque.append.__module__
   Traceback (most recent call last):
     File "<python-input-15>", line 1, in <module>
       collections.deque.append.__module__
   AttributeError: 'method_descriptor' object has no attribute '__module__'. Did you mean: '__reduce__'?
   >>> collections.deque().append.__module__ is None
   True

   We should first decide whether we need the __module__ attribute for regular builtin methods.
9. skirpichev commented on Nov 2, 2024

   

   skirpichev

   on Nov 2, 2024

   MemberAuthor

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   We should first decide whether we need the __module__ attribute for regular builtin methods.

   That should be helpful for introspection. E.g. now the inspect._signature_fromstr() resolves module_dict to empty for e.g. bytes.maketrans() or int.from_bytes(). That essentially forbids e.g. using module constants as default values.
10. picnixz

    added

    interpreter-core(Objects, Python, Grammar, and Parser dirs)(Objects, Python, Grammar, and Parser dirs)

    and removed

    3.14bugs and security fixesbugs and security fixes

    on Dec 15, 2024
11. skirpichev

    assigned

    skirpichev

    and unassigned

    skirpichev

    on Sep 9, 2025
12. skirpichev

    self-assigned this

    on Oct 14, 2025
13. skirpichev

    removed their assignment

    on Oct 27, 2025
14. vstinner

    added a commit that references this issue on Feb 2, 2026

    gh-115231: Fill __module__ for built-in staticmethods (#115232)

    15c9f24
15. Aniketsy

    added a commit that references this issue on Feb 3, 2026

    pythongh-115231: Fill __module__ for built-in staticmethods (python#1…

    a09aa1e
16. thunder-coding

    added a commit that references this issue on Feb 15, 2026

    pythongh-115231: Fill __module__ for built-in staticmethods (python#1…

    3e81347
17. hugovk

    closed this as completedon Oct 23, 2026

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