question to the signature of list.index

[weipeng1999]

Recently I switch to use pyright as my lsp server. This server is very strict at type annotation, and I found some errors as following.

  error: Type "list[int]" is not assignable to declared type "SequenceNotStr[int]"
    "list[int]" is incompatible with protocol "SequenceNotStr[int]"
      "index" is an incompatible type
        Type "(value: int, start: SupportsIndex = 0, stop: SupportsIndex = sys.maxsize, /) -> int" is not assignable to type "(value: Any, /, start: int = 0, stop: int = ...) -> int"
          Missing keyword parameter "start"
          Missing keyword parameter "stop"
            Position-only parameter mismatch; parameter "start" is not position-only
            Position-only parameter mismatch; parameter "stop" is not position-only (reportAssignmentType)
1 error, 0 warnings, 0 informations

so I check the "index" signature of list.index and SequenceNotStr.index, found that:

>>> inspect.signature(list.index)
<Signature (self, value, start=0, stop=9223372036854775807, /)>
>>> inspect.signature(pd_typing.SequenceNotStr.index)
<Signature (self, value: 'Any', /, start: 'int' = 0, stop: 'int' = Ellipsis) -> 'int'>

The signature of list.index make me surprised. Why we set start and stop as the position-only argument to the list.index? I think defined them as position-and-keyword argument is a better idea, so that we can using keyword to set them. Meanwhile i think give default value to position-only argument is a little strange

[JelleZijlstra]

I think the typing issue you see was fixed in hauntsaninja/useful_types#23 last year. We could give list.index positional-or-keyword arguments but I don't feel strongly.

[weipeng1999]

I think the typing issue you see was fixed in hauntsaninja/useful_types#23 last year. We could give list.index positional-or-keyword arguments but I don't feel strongly.

Thanks for reply, but the SequenceNotStr is pandas._typing.SequenceNotStr, so it still not fix for me (its my wrong that not clearify which package the SequenceNotStr is provided). But I think this show that more third party typing system set the arguments as position-and-keyword, so this question may be more important than we think.

[JelleZijlstra]

Well, then this is a bug in pandas.

[weipeng1999]

Well, then this is a bug in pandas.

even this is a bug and we keep old behaviour, maybe at least we should clearly set the argument type of this two parameters in python standard document to guild third party package what is the correct signature of index?

[feoh]

@weipeng1999 Pardon my ignorance, but could you please include a code snippet that's causing pyright to emit that error?

[AA-Turner]

Closing, for help please use other fora.

A