python初学者，验证密码是否符合要求问题，在写验证这部分时不会了

Question

python初学者，验证密码是否符合要求问题，在写验证这部分时不会了

"""
Please enter a valid password
Your password must be between 5 and 15 characters, and contain:
1 or more uppercase characters
1 or more lowercase characters
1 or more numbers and 1 or more special characters: !@#$%^&*()_-=+`~,./'[]<>?{}|\
"""

MIN_LENGTH = 5
MAX_LENGTH = 15
SPECIAL_CHARS_REQUIRED = False
SPECIAL_CHARACTERS = "!@#$%^&*()_-=+`~,./'[]<>?{}|\\"


def main():
    """Program to get and check a user's password."""
    print("Please enter a valid password")
    print("Your password must be between", MIN_LENGTH, "and", MAX_LENGTH,
          "characters, and contain:")
    print("\t1 or more uppercase characters")
    print("\t1 or more lowercase characters")
    print("\t1 or more numbers")
    if SPECIAL_CHARS_REQUIRED:
        print("\tand 1 or more special characters: ", SPECIAL_CHARACTERS)
    password = input("> ")
    while not is_valid_password(password):
        print("Invalid password!")
        password = input("> ")
    print("Your {}-character password is valid: {}".format(len(password),
                                                           password))


def is_valid_password(password):
    """Determine if the provided password is valid."""
    # TODO: if length is wrong, return False

    count_lower = 0
    count_upper = 0
    count_digit = 0
    count_special = 0
    for char in password:
        # TODO: count each kind of character (use str methods like isdigit)
        pass

    # TODO: if any of the 'normal' counts are zero, return False

    # TODO: if special characters are required, then check the count of those
    # and return False if it's zero

    # if we get here (without returning False), then the password must be valid
    return True


main()

上面在验证密码函数部分，原题已经给了注释，我这部分卡住了，写不出来，麻烦看一下，给一个完整补充好的代码，如果能有详细一点的注释就更好啦，谢谢

Answer 1

MIN_LENGTH = 5
MAX_LENGTH = 15
SPECIAL_CHARS_REQUIRED = False
SPECIAL_CHARACTERS = "!@#$%^&*()_-=+`~,./'[]<>?{}|\\"
def  main():
    """Program to get and check a user's password."""
    print("Please enter a valid password")
    print("Your password must be between", MIN_LENGTH, "and", MAX_LENGTH,
          "characters, and contain:")
    print("\t1 or more uppercase characters")
    print("\t1 or more lowercase characters")
    print("\t1 or more numbers")
    if SPECIAL_CHARS_REQUIRED:
        print("\tand 1 or more special characters: ", SPECIAL_CHARACTERS)
    password = input("> ")
    while not is_valid_password(password):
        print("Invalid password!")
        password = input("> ")
    print("Your {}-character password is valid: {}".format(len(password),
                                                           password))
 
 
def is_valid_password(password):
    if len(password)<MIN_LENGTH or len(password)>MAX_LENGTH:
        return False
    count_lower = 0
    count_upper = 0
    count_digit = 0
    count_special = 0
    for char in password:
        if char.isdigit():
            count_digit+=1
        elif char.isupper():
            count_upper+=1
        elif char.islower():
            count_lower+=1
        elif char in SPECIAL_CHARACTERS:
            count_special+=1

    if count_lower==0 or count_upper==0 or count_digit==0:
        return False
    if SPECIAL_CHARS_REQUIRED and count_special==0:
        return False
    return True

main()