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unnecessary-literal-union (PYI030)

Added in v0.0.278 · Related issues · View source

Derived from the flake8-pyi linter.

Fix is sometimes available.

What it does

Checks for the presence of multiple literal types in a union.

Why is this bad?

Literal["foo", 42] has identical semantics to Literal["foo"] | Literal[42], but is clearer and more concise.

Example

from typing import Literal

field: Literal[1] | Literal[2] | str

Use instead:

from typing import Literal

field: Literal[1, 2] | str

Fix safety

This fix is marked unsafe if it would delete any comments within the replacement range.

An example to illustrate where comments are preserved and where they are not:

from typing import Literal

field: (
    # deleted comment
    Literal["a", "b"]  # deleted comment
    # deleted comment
    | Literal["c", "d"]  # preserved comment
)

References