python hashlib md5算法加密用戶密碼登錄程序

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import hashlib

def md5(arg):
    '''
    用於把用戶的密碼加密
    '''
    md5 = hashlib.md5()
    md5.update(bytes(arg, encoding='utf-8'))
    return md5.hexdigest()
def register(user,passwd):
#用戶註冊的時候把密碼加密添加到文件
    with open("db", 'a') as f:
        tmp = "\n" + user + "|"+ md5(passwd)
        f.write(tmp)
        return True
def login(user,passwd):
#用戶登錄時候認證
    with open('db','r') as f:
        for i in f:
            c = i.strip()
            s = c.split("|")
            if s[0]== user and s[1] == md5(passwd):
                return True
sum = input("1登錄 2註冊：")
if sum == "1"or sum == "2":
    user = input("請輸入賬號:")
    passwd = input("請輸入密碼:")
    if sum =="1":
        if login(user,passwd):
            print("登錄成功")
        else:
            print("登錄失敗")
    if sum =="2":
        if register(user,passwd):
            print("註冊成功")
else:
    print("輸入錯誤")