python中MD5的demo

import sys
import hashlib

class user(object):
	# 类比数据库
    db = dict()
    
    # 根据用户的登录名和口令，生成更安全的口令
    def register(self,username,password):
        if username in self.db:
            print 'This username %s is already exist!' % username
            # 终止程序，跟java类似
            sys.exit(0)
        # 用户名 没有被注册  pasword+username+盐 来生成复杂的密码
        realPassword=password+username+'The-Salt'
        md5=hashlib.md5()
        md5.update(realPassword)
        resultPassword=md5.hexdigest()
        self.db.setdefault(username,resultPassword)
        print 'Register Success,%s' % username

    # 验证用户登录的函数
    def login(self,username, password):
        for k, v in self.db.items():
            if username == k:
                md5 = hashlib.md5()
                md5.update(password+username+'The-Salt')
                pw = md5.hexdigest()
                if pw == v:
                    return True
        return False


if __name__ == '__main__':
    u=user()
    u.register('Caren','123456')
    flag=u.login('Caren','123456')
    if flag:
        print '登录成功！'
    else:
        print '用户名或密码不正确！'
    print u.db