Fix incorrect keyword-only arguments in tarfile.open()

[edwardpeek-crown-public]

Per https://docs.python.org/3/library/tarfile.html#tarfile.open all of name, mode, fileobj, and bufsize are permitted to be positional.

[edwardpeek-crown-public]

Took me a while to wrap my head around the signature duplication, but I think this fixes the overly constrained pipe modes (from #13130) in the right spirit.

[hauntsaninja]

Could you add a test case corresponding to the thing you'd like to pass type check to stdlib/@tests/test_cases/check_tarfile.py?

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

vision (https://github.com/pytorch/vision)
+ torchvision/datasets/utils.py:215: note:     def open(cls, name: str | bytes | PathLike[str] | PathLike[bytes] | Buffer | None, mode: Literal['r|*', 'r|', 'r|gz', 'r|bz2', 'r|xz'], fileobj: _Fileobj | None = ..., bufsize: int = ..., *, format: int | None = ..., tarinfo: type[TarInfo] | None = ..., dereference: bool | None = ..., ignore_zeros: bool | None = ..., encoding: str | None = ..., errors: str = ..., pax_headers: Mapping[str, str] | None = ..., debug: int | None = ..., errorlevel: int | None = ...) -> TarFile
+ torchvision/datasets/utils.py:215: note:     def open(cls, name: str | bytes | PathLike[str] | PathLike[bytes] | Buffer | None, mode: Literal['w|', 'w|xz'], fileobj: _Fileobj | None = ..., bufsize: int = ..., *, format: int | None = ..., tarinfo: type[TarInfo] | None = ..., dereference: bool | None = ..., ignore_zeros: bool | None = ..., encoding: str | None = ..., errors: str = ..., pax_headers: Mapping[str, str] | None = ..., debug: int | None = ..., errorlevel: int | None = ...) -> TarFile
+ torchvision/datasets/utils.py:215: note:     def open(cls, name: str | bytes | PathLike[str] | PathLike[bytes] | Buffer | None, mode: Literal['w|gz', 'w|bz2'], fileobj: _Fileobj | None = ..., bufsize: int = ..., *, format: int | None = ..., tarinfo: type[TarInfo] | None = ..., dereference: bool | None = ..., ignore_zeros: bool | None = ..., encoding: str | None = ..., errors: str = ..., pax_headers: Mapping[str, str] | None = ..., debug: int | None = ..., errorlevel: int | None = ..., compresslevel: int = ...) -> TarFile

[srittau]

Thanks!

Unfortunately, the fact that arguments with defaults can't precede arguments without defaults makes these extra overloads necessary. This was previously discussed on the typing-sig mailing list and subsequently on the python-dev mailing list. Maybe it's time to resurrect that proposal, possibly with the support of the typing council.