from random import Random#随机生成4到20位的用户名def random_username(): username = '' chars = 'AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz0123456789-_' length = len(chars) - 1 random = Random() for i in range(4,20): username +=chars[random.randint(0,…