思维导图：

需求：输入用户名和密码，认证后显示欢迎信息，输错三次后锁定

 

#!/usr/bin/env python

#coding:utf-8import MySQLdbconn=MySQLdb.connect(user='root',passwd='123456',host='192.168.2.71',db='login')cur=conn.cursor()cur_user=conn.cursor()cur_user.execute("select * from t_account")cur.execute("select * from lock_account")user_names=cur_user.fetchall()lock_names=cur.fetchall()

login_names={}#转换用户名和密码

for name,passwd in user_names:    login_names[name]=login_names.get(name,passwd)print login_names

lock_users=[]  #获取已经锁过的账号

for name in lock_names:    names=name[1]    lock_users.append(names)print lock_users

retry_counter = 0

while retry_counter < 3 :#循环三次      user = raw_input('Username:').strip()    if len(user) ==0:                       #账号不为空     print "Username cannot be empty!"     continue    if user in lock_users:        print "username is already locked"        break      passwd = raw_input('Password:').strip()      if user in login_names and passwd==login_names[user]:        print login_names[user]        print "Welcome %s loging my system" % user        break    else:        retry_counter+=1else:    cur.execute("insert into lock_account(name) values(%s)",user)    conn.commit()    print lock_users    print "Your are not allowed to login!,now will lock %s account" % user