docs: def load_auth_from_file(filename):
      """Initializes the auth settings for accessing MyAnimelist through its
      official API from a given filename.
      :param filename The name of the file containing your MyAnimeList
                      credentials
                      REQUIREMENTS: The file must...
                          ...username for your MAL account.
                          ...password for your MAL account.
                          ...Have both your username  and password
                          ...separated by newline(s) or space(s).
      :return A tuple containing your credentials.
      """
      with open(filename) as auth_file:
          lines = auth_file.read().splitlines()
          lines = [line.strip() for line in lines if len(line) != 0]
          if len(lines) == 2:
              credentials = (lines[0], lines[1])
          elif len(lines) == 1:
              user_pass = lines[0].split()
              credentials = (user_pass[0], user_pass[1])
          elif len(lines) == 0 or len(lines) > 2:
              raise ValueError(constants.INVALID_AUTH_FILE)
  
          if helpers.verif_auth(credentials, header):
              return credentials
          else:
              raise ValueError(constants.INVALID_CREDENTIALS)