code: def natural_keys(input_str: str) -> List[Union[int, str]]:
      
      return [try_int_or_force_to_lower_case(substr) for substr in re.split(r'(\d+)', input_str)]
docs: Converts a string into a list of integers and strings to support natural sorting (see natural_sort).
  
      For example: natural_keys('abc123def') -> ['abc', '123', 'def']
      :param input_str: string to convert
      :return: list of strings and integers