python type hints return code example

Example 1: python function argument type

def pick(l: list, index: int) -> int:
    return l[index]

Example 2: python type hints

def no_type_hint(arg):
  print(arg) # arg can be anything
  
def with_type_hint(arg: str):
  print(arg) # arg must be a string or a subtype of string

Example 3: python typing list of strings

from typing import List

def my_func(l: List[int]):
    pass