typevar-name-incorrect-variance / C0105#
Type variable name does not reflect variance%s
Emitted when a TypeVar name doesn't reflect its type variance. According to PEP8, it is recommended to add suffixes '_co' and '_contra' to the variables used to declare covariant or contravariant behaviour respectively. Invariant (default) variables do not require a suffix. The message is also emitted when invariant variables do have a suffix.
from typing import TypeVar T_co = TypeVar("T_co") # [typevar-name-incorrect-variance]
from typing import TypeVar T = TypeVar("T")
Created by the basic checker.