import text #text为文件名:text.py 用来实现文件验证

print("欢迎使用登陆")

username = input("请输入用户名：")

while text.CheckUsername(username)==-1:

  username = input("没有该用户\n请输入用户名:")

else:

  n=text.CheckUsername(username)

  password = input("请输入密码：")

  text.CheckUser(n,password)

import pickle

def CheckUsername(name):#检验是否有该用户名

  ff = open("D:\\test.txt", "rb")

  n = pickle.load(ff)

  # print(n)

  # print(n[0][0])

  # print(len(n))

  ff.close()

  for i in range(len(n)):

    if name == n[i][0]:

      return i

  return -1#用来返回用户名所在位置

def CheckUser(x,psd):#x为用户名位置，pwd为密码

  ff = open("D:\\test.txt", "rb")

  n = pickle.load(ff)

  # print(n)

  # print(n[0][0])

  # print(len(n))

  ff.close()

  i=1

  while n[x][1]!=psd and i<3:

    psd=input("请再次输入密码：")

    i+=1

  else:

    if i<3:

      print("登陆成功！")

    else:

      print("3次输入密码错误！已锁定")

import pickle

s=[["aaa","111"],["bbb","222"],["ccc","333"]]

f = open("D:\\test.txt","wb")

try:

  pickle.dump(s,f)

except:

  print("输入异常")

finally:

  f.close()