案例：MD5用户注册密码加密摘要

加盐：

md5 = hashlib.md5(bytes('cheng', encoding='utf-8'))

 

import hashlib
def zhuce():
    print('\n', '用户注册'.center(30, '-'), '\n')
    usr_name = input('请输入姓名：')                               # 获取用户信息
    usr_id = input('请输入用户名：')
    usr_pwd = input('请输入密码：')
    with open('file', 'a',  encoding='utf-8') as f:
        md5 = hashlib.md5()
        md5.update(bytes(usr_pwd, encoding='utf-8'))
        usr_pwd = md5.hexdigest()                                # 密码摘要转换MD5
        usr_info = '%s|%s|%s\n' %(usr_name, usr_id, usr_pwd)
        f.write(usr_info)                                        # 将转换后的pwd以及未转换的id、name写入文件
    print('\n', '注册成功'.center(30, '-'))

def login():
    print('\n', '用户登陆'.center(30, '-'), '\n')
    new_usr_id = input('请输入用户名：')
    new_usr_pwd = input('请输入密码：')
    md5 = hashlib.md5()
    md5.update(bytes(new_usr_pwd, encoding='utf-8'))
    new_usr_pwd = md5.hexdigest()
    with open('file', encoding='utf-8') as f:
        for line in f:
            usr_name, usr_id, usr_pwd = line.split('|')
            a_pwd = usr_pwd.strip()
            if a_pwd == new_usr_pwd and new_usr_id == usr_id:
                print('\n', '登陆成功'.center(30, '-'))
                print('\n', '欢迎 %s'.center(30, '-')% usr_name)
                break
        else:
            print('登陆失败')
            print('用户名或密码错误')


while True:
    print('''
    ********* 请选择 *********
        
    -------> 1.登陆
    -------> 2.注册
    -------> 3.退出
    ''')
    usr_choice = input('>>:')
    if usr_choice == '1':
        login()
    elif usr_choice == '2':
        zhuce()
    elif usr_choice == '3':
        break