`tarfile.TarFile` has several missing overloads · python/typeshed#14168

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help wantedstubs: false negative

説明

Right now TarFile.__init__ is defined as: https://github.com/python/typeshed/blob/c7e29eccd9759411c0f46580e20727038668b320/stdlib/tarfile.pyi#L128-L132

Which is not exactly right, because there's a case when name and fileobj are both None at the same time. And this will lead to runtime errors:

>>> import tarfile
>>> tarfile.TarFile(None, fileobj=None)
Traceback (most recent call last):
  File "<python-input-2>", line 1, in <module>
    tarfile.TarFile(None, fileobj=None)
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
  File "/Users/sobolev/Desktop/cpython/Lib/tarfile.py", line 1729, in __init__
    fileobj = bltn_open(name, self._mode)
TypeError: expected str, bytes or os.PathLike object, not NoneType

Right now mypy does not raise any errors for this broken case: https://mypy-play.net/?mypy=latest&python=3.12&gist=7452d274249fafba1f8a16565d5486c6

We need either name or fileobj, they can be both None at the same time. So, we need to add overloads.

There are several other methods that needs to be updated like open and taropen, maybe others.

コントリビューターガイド

技術スタック: python
領域: developer experiencetooling
Issue 種別: bug
難度: 3
推定時間: 1-3 hours
活動状況: fresh
明確さ: mostly clear
前提条件: Basic knowledge of Python type hintsUnderstanding of function overloads
初心者向け度: 50
調査方針: The issue is that `TarFile. init ` and other methods like `open` and `taropen` need overloads to enforce that at least one of `name` or `fileobj` is provided. Look at the existing stub file at `stdlib/tarfile.pyi` and examine how other overloads are defined in typeshed (e.g., for `open` functions). The goal is to define two overloads: one with `name: str` and `fileobj: None`, another with `name: None` and `fileobj: IO[bytes]`. Ensure the original signature is kept as a fallback. Check the comments on the issue for any additional context.