Python开发之【用户登录锁定】

用户登录验证，输入密码错误三次，锁定此用户。 将用户信息存入文件

文件内容格式如下：

{'username':'heilong','password':'123456','login_flag':True}
{'username':'dong','password':'23456','login_flag':True}
{'username':'bin','password':'3456','login_flag':False}
{'username':'dun','password':'456','login_flag':False}
{'username':'ke','password':'56','login_flag':False}

import os

file_ismodify = False

username_in = input("请输入用户名：")
with open("login_lock", "r", encoding="utf-8") as read_file, 
        open("login_lock_new", "w", encoding="utf-8") as write_file:
    for line in read_file:
        if eval(line)["username"] == username_in:
            if eval(line)["login_flag"]:
                print("您的账号被锁定，拒绝登录！")
                break
            else:
                count = 0
                while count < 3:
                    password_in = input("请输入密码：")
                    if eval(line)["password"] == password_in:
                        print("登录成功！")
                        break
                    else:
                        if count != 2:
                            print("登录失败,您还有%s次机会" % (2 - count))
                        else:
                            print("三次输入用户名或密码错误，拒绝登录！")
                            write_file.write("{'username':'%s','password':'%s','login_flag':%s}
"
                                                  %(username_in,eval(line)["password"],True))
                            file_ismodify = True
                            break
                    count += 1
        else:
            write_file.write(line)

if file_ismodify:
    os.rename("login_lock","login_lock.bak")
    os.rename("login_lock_new","login_lock")
    os.remove("login_lock.bak")
else:
    os.remove("login_lock_new")