unprefixed-type-param (PYI001)

Derived from the flake8-pyi linter.

What it does

Checks that type TypeVars, ParamSpecs, and TypeVarTuples in stubs have names prefixed with _.

Why is this bad?

Prefixing type parameters with _ avoids accidentally exposing names internal to the stub.

Example

from typing import TypeVar

T = TypeVar("T")

Use instead:

from typing import TypeVar

_T = TypeVar("_T")