def create_phone_number(n): # my_list = [str(i) for i in n] # return "({}) {}-{}".format(''.join(my_list[:3]), ''.join(my_list[3:6]), ''.join(my_list[6:])) return "({}{}{}) {}{}{}-{}{}{}{}".format(*n) numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0] print(create_phone_number(numbers))