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redundant-none-literal (PYI061)

Derived from the flake8-pyi linter.

Fix is sometimes available.

This rule is unstable and in preview. The --preview flag is required for use.

What it does

Checks for redundant Literal[None] annotations.

Why is this bad?

While Literal[None] is a valid type annotation, it is semantically equivalent to None. Prefer None over Literal[None] for both consistency and readability.

Example

from typing import Literal

Literal[None]
Literal[1, 2, 3, "foo", 5, None]

Use instead:

from typing import Literal

None
Literal[1, 2, 3, "foo", 5] | None

Fix safety and availability

This rule's fix is marked as safe unless the literal contains comments.

There is currently no fix available when applying the fix would lead to a TypeError from an expression of the form None | None or when we are unable to import the symbol typing.Optional and the Python version is 3.9 or below.

References