python 自学day1（关于if和file的应用练习）

1.编写简单的登陆接口

#判断用户信息

#用户输入错误后锁定账号

流程图：

代码：

#！/usr/bin/env python

#-*- coding:utf-8 -*-

document1 = open('userinfo.txt', 'r')
document2 = open('falseuser.tex', 'w+')
document3 = open('lock.txt', 'w+')
i = 1
n = 1
while i < 4 and n < 4:
    username = input('username:')
    password = input('password:')
    str1 = document1.read()
    h = len(username)
    if str1.find(username) >= 0 and document2.read().find(username) == -1:
        if str1.find(password, (str1.find(username)+h+1), len(password)):
            print('welcome to our web!')
            break
        else:
            document2.write(username)
            i += 1
    else:
        if document2.read().find(username) >= 0:
            if str1.find(password, (str1.find(username)+h+1), len(password)) and document3.read().find(username) == -1:
                print('welcome to our web!')
            elif document3.read().find(username) != -1:
                print('you have try 3 times')
                break
            else:
                i += 1
                print('confirm password')
        else:
            print('plese input right username')
            n += 1
while i == 3:
    document3.write(username)
document3.close()
document2.close()
document1.close()
pycharm python3.7版本可用。