9-26 联合文件的登录注册

username = input('请输入你要注册的用户名:')
password = input('请输入你要注册的密码:')
with open('info',mode = 'w',encoding = 'utf-8') as f:
    f.write('{}\n{}'.format(username,password))
print('注册成功！')
i = 0
li = []
while i < 3:
    usn = input('请输入用户名：')
    psd = input('请输入密码：')
    with open('info',mode = 'r',encoding='utf-8') as f1:
        for line in f1:
            li.append(line)
    if li[0].strip() == usn and li[1].strip() == psd:
        print('登录成功！')
        break
    else:
        print('用户信息错误，您还有%d次重新输入的机会'%(2-i))
    i += 1