Skip to content

redundant-numeric-union (PYI041)#

Derived from the flake8-pyi linter.

What it does#

Checks for union annotations that contain redundant numeric types (e.g., int | float).

Why is this bad?#

In Python, int is a subtype of float, and float is a subtype of complex. As such, a union that includes both int and float is redundant, as it is equivalent to a union that only includes float.

For more, see PEP 3141, which defines Python's "numeric tower".

Unions with redundant elements are less readable than unions without them.

Example#

def foo(x: float | int) -> None:
    ...

Use instead: 

def foo(x: float) -> None:
    ...

References#