Why do I get a warning when concatenating lists of mixed types in Pycharm?

Question

In Pycharm, the following code produces a warning:

from typing import List

list1: List[int] = [1, 2, 3]
list2: List[s         


        

Answer 1

Like Pycharm says it's just a warning you are allowed to concatenate different objects or lists but it is considered to be a bad practice.