non-pep646-unpack (UP044)

Added in 0.10.0 · Related issues · View source

Derived from the pyupgrade linter.

Fix is always available.

What it does

Checks for uses of Unpack[] on Python 3.11 and above, and suggests using * instead.

Why is this bad?

PEP 646 introduced a new syntax for unpacking sequences based on the * operator. This syntax is more concise and readable than the previous Unpack[] syntax.

Example

from typing import Unpack


def foo(*args: Unpack[tuple[int, ...]]) -> None:
    pass

Use instead:

def foo(*args: *tuple[int, ...]) -> None:
    pass

Fix safety

This rule's fix is marked as unsafe, as Unpack[T] and *T are considered different values when introspecting types at runtime. However, in most cases, the fix should be safe to apply.