python random() 简单实现验证码

import random
while True:
    code = ''
    for i in range(4):
        current = random.randrange(0,4)
        if current == i:
            temp = chr(random.randint(65,90))
        else:
            temp = str(random.randint(0,9))
        code+=temp
    print(code)
    input_user = input("请输入验证码：")
    if input_user == code:
        print("。。。。。。。。。欢迎。。。。。。。")
        break
    else:
        print("您输入的验证码不正确。")