Python初学者遇到的基础问题

我这个是一个基础密码检查的代码，代码没问题，如果再次基础上再单独定义一个函数，有一个要求是可以实现在输入时不会显示密码而是显示*，麻烦看一下，给一个修改后的代码，谢谢啦

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()

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()

在pycharm命令行不行，要在终端运行才能生效：

import getpass

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 = getpass.getpass("> ")
    while not is_valid_password(password):
        print("Invalid password!")
        password = getpass.getpass("> ")
    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()

• 你可以参考下这篇文章：python初学者常见的错误