检查密码的安全性

# -*- coding:utf-8 -*-

def myallin(input, check):
    r = 1
    for ch in input:
        if not(ch in check): r = 0
    return r

def myin(input, check):
    for ch in input:
        if ch in check: return 1
    return 0

letter="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
num="0123456789"
char='~!@#$%^&*()_=-/,.?<>;:[]{}|\\'
passwd = input("请输入要检查的密码: ")
if (len(passwd)<=7):
    print('输入的密码 {} 过短'.format(str(passwd)))
elif (len(passwd)>20): #假设最长20:
    print('输入的密码 {} 过长'.format(str(passwd)))
elif myallin(passwd, letter) or myallin(passwd, num): #全是数字/字母
    print('输入密码为高危')
elif myin(passwd, letter) and myin(passwd, num) and myin(passwd, char) and len(passwd)>=8: #包含字母数字符号并且长度>8
    print('输入密码为低危')
else:
    print('输入的密码为中危')