第一天的作业，登录接口脚本 login.py

 user_list = []
 count = 0
 user = "liruixin"
 password = ""
 raw_user = raw_input("username:")
 f=open("user.txt",'r')
 lines=[]
 for lines in f.readlines():
     lines=lines.replace("\n","").split(",")
 f.close()
 for i in lines:
     if i == raw_user:
         print "this user is locked, please request to root"
         exit()
     else:
         pass
 while count <3:
     if raw_user == user:
         raw_password = raw_input("password:")
         count = count+1
         if count == 3:
             user_list.append(raw_user)
             user = open('user.txt','a')
             for raw_user in user_list:
                 user.write(raw_user + ',')
             user.close()
         else:
             pass
         if raw_password == password:
             print "success"
             exit()
         else:
             print "this password error"
     else:
         print "no this user"
         exit()
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