python - 如何确保输入满足要求

Question

用户必须输入密码，但密码中必须至少有1个大写、小写和数字。

password = input("Please enter a password: ")

Answer 1

if any(x.isupper() for x in password) and \ 
   any(x.islower() for x in password) and \
   any(x.isdigit() for x in password):
    print ("Congratulations, you have a secure password.")

Answer 2

您还可以放入一个在匹配这些条件之前不会停止的 while 循环：

while True:
     password = input("Please enter a password: ")
     if any(x.isupper() for x in password) and \ 
        any(x.islower() for x in password) and \
        any(x.isdigit() for x in password): #copy from Rob's awnser
            break

     else: print('Invalid!')