python - 密码验证器: password needs to contain EXACTLY one spacial character?

Question

Task: Password validator
a. The length of the password needs to be from 8 to 30 characters.
b. The password needs to contain at least 2 uppercase characters.
c. The password needs to contain at least 2 lowercase characters.
d. The password needs to contain at least 1 digit.
e. The password needs to contain exactly 1, but not more of the following special characters:
@/%&*_-

这是我的代码:

special_character_set = "@/%&*_-"
is_valid = False
import re
while True:
    password = input("please enter a password: ")
    if len(password) > 30 or len(password)< 8:
        print("The length of the password needs to be from 8 to 30 characters!")
        continue
    elif re.search('[0-9]', password) is None:
        print("The password needs to contain at least 1 digit!")
        continue
    elif re.search ('[A-Z][A-Z]', password) is None:
        print("The password needs to contain at least 2 uppercase characters!")
        continue
    elif re.search('[a-z][a-z]', password) is None:
        print("The password needs to contain at least 2 lowercase characters!")
        continue
    elif re.search('[@/%&*_-]', password) is None:
        print("The password needs to contain one of the following special characters: @/%&*_-!")
        continue
    else:
        is_valid = True
    if is_valid:
        print("valid password")
        break

它有效。然而，条件e)尚未完全满足。如何使密码仅包含一个特殊字符？

Answer 1

len + re.findall() 怎么样？ :

...
elif len(re.findall('[@/%&*_-]', password)) != 1:
    # Some number of special characters other than 1 was found
    ...

或

...
elif len(re.findall('[@/%&*_-]', password)) == 0:
    # No special characters were found
    ...
elif len(re.findall('[@/%&*_-]', password)) > 1:
    # Too many special characters were found

(如果您执行后者，请尽量不要运行正则表达式两次)