How to properly function annotate / type hint a list of strings

Question

I am trying to figure out how to properly function annotate or type hint a list of strings. For example, if I had a function like this:

def send_email(self,         


        

Answer 1

You need to import

from typing import List
List[str]

Note the capital L.

In python 3.9+ the lower case l also supports generics.

You might want to consider something more specific. Why is to_adress a Str, but from_Adress is a List[Str]? Maybe a

Adress = typing.NewType("Adress")

is helpful.