`PyArg_UnpackTuple` is used with `name=""`

[denballakh]

Bug report

Bug description:

PyArg_UnpackTuple(args, "", causes empty name to be used in error messages:

>>> str.join.__get__()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError:  expected at least 1 argument, got 0
#         ^^

>>> try: str.join.__get__()
... except Exception as e: exc = e
...
>>> str(exc)
' expected at least 1 argument, got 0'
#^

According to my quick search, PyArg_UnpackTuple(args, "", is used 10 times in Objects/typeobject.c and 3 times in Modules/_csv.c.

CPython versions tested on:

3.12, CPython main branch

Operating systems tested on:

No response

Linked PRs

• gh-123446: Fix empty function names in TypeErrors in _csv module #123461
• gh-123446: Fix empty function names in TypeErrors in _csv module (follow-up to gh-123461) #123462
• [3.12] gh-123446: Fix empty function names in TypeErrors in _csv module (GH-123462) #123466
• gh-123446: Fix empty function names in TypeErrors in typeobject #123470

[serhiy-storchaka]

I agree, this is a misuse. The right use is to pass NULL as the name, or better provide some related name if this is possible.