type-param-name-mismatch (PLC0132)

Derived from the Pylint linter.

What it does

Checks for TypeVar, TypeVarTuple, ParamSpec, and NewType definitions in which the name of the type parameter does not match the name of the variable to which it is assigned.

Why is this bad?

When defining a TypeVar or a related type parameter, Python allows you to provide a name for the type parameter. According to PEP 484, the name provided to the TypeVar constructor must be equal to the name of the variable to which it is assigned.

Example

from typing import TypeVar

T = TypeVar("U")

Use instead:

from typing import TypeVar

T = TypeVar("T")

References

• Python documentation: typing — Support for type hints
• PEP 484 – Type Hints: Generics