Python-S13-day1                                

需求：

1.让用户输入账号密码，账号密码正确，登陆程序，打印欢迎信息；

2.如果账号，或密码输入错误，提示用户重新输入，用户有三次机会；

3.如果用户第三次输入的账号或者密码还是不正确，就把第三次输入的账号锁定。

主程序：

#!/usr/bin/python env #_*_coding:utf-8 _*_ userfile1='userfile' lockfile1='lockfile' userfile=open(userfile1,'r+') lockfile=open(lockfile1,'r+') login_flag = False #设置一个标志位，用于判断用户是否登陆成功； for i in range(3): username=input("username:") for lockuser in lockfile.readlines(): lockuser = lockuser.split() #把被锁定的账号，转换成一个列表； if username in lockuser: #判断账号是否在锁定列表中，如果在，就退出； exit("%s user is lock"%username) password = input("password:") for line in userfile.readlines(): line = line.split() #把允许登陆的用户名，密码转换成列表； user = line[0] #把登陆账号赋值给user passwd = line[1] #把登陆密码赋值给passwd if user == username and passwd == password: #判断账号，密码是否正确，如果正确，登陆并打印欢迎信息； exit("welcomto login.") login_flag = True #标志位，判断用户是否登陆成功； if login_flag == False: print("user or passwd error.") else: print("%s user is lock."%username) lockfile.write("\t%s"%username) lockfile.close() #循环三次后，用户还没有登陆成功，就把账号锁定；

Readme：

1.这个程序一共三个文件：userfile存放登陆账号，密码的文件；

　　　　　　　　　　　　lockfile存放被锁定的账号；

　　　　　　　　　　　　login.py登陆主程序；

流程图：

 

思路二（功能全部实现）：

#!/usr/bin/python env#_*_coding:utf-8 _*_user = open('db','r+')lock = open('db1','r+')mark = Falsefor i in range(3):    username = input("input user name:")    for line in lock.readlines():        line = line.split("|")    if username in line:        exit("user is lock.")    passwd = input("input you password.")    for pwd in user.readlines():        pwd = pwd.split("|")        if pwd[0] == username and pwd[1].strip("\n") == passwd:            exit("welcoto login.")    else:        print('user or passwd error.')else:    print("%s user is lock"%username)    lockuser = open('db1','a')    lockuser.write("|"+"%s"%username)    lockuser.close() * lockuser.txt 0||1|11

*loginuser.txt admin|123 freddy|123

 思路三（函数写法）：

#用户输入三次，密码不正确，锁定账号，功能没有实现； def register(user,pwd):    reg = open('db','a')    reg.write("\n" + user + "|" + pwd )    reg.close()def login (user,pwd):    lockuser = open('db1','r')    for line in lockuser.readlines():        line = line.split("|")        if user in line:            exit("user is lock.")    userpwd = open('db','r')    for logpwd in userpwd:        logpwd = logpwd.split("|")        if user == logpwd[0] and pwd == logpwd[1].strip("\n"):            exit("welcome to login")    else:        print("user or password error")    input_num = input("input y or n.")    if input_num == 'y':        main()    else:        exit()def main():    choice = input("1.register.  2.login.")    if choice == '1':        username = input("username:")        password = input("password:")        register(username,password)    elif choice == '2':        username = input("username:")        password = input("password:")        login(username,password)main()