I want to define an interface for a data class, but leave open the way the data is stored. To this end, I define a protocol A for the interface and an implementation B:

I can write a function like

Here’s a trivial example, but something which I’m trying to make use of in a project.

from typing import Never def some_func() -> list[int] | list[Never]: … What does list[Never] means? Thanks in advance fellow users from the wonderful website stackoverflow, which obliges me to enter at least 220 characters. python typing