def check_code(): import random checkcode = "" for i in range(4): current = random.randrange(0,4) if current != i: temp = chr(random.randint(65,90)) else: temp = random.randint(0,9) checkcode += str(temp) return checkcode while 1: code = check_code() print(code) user = input("请输入验证码:") if user == code: print("正确") break else: print("不正确")