用戶登陸python腳本

用戶登陸，用已知的user和passwd登陸，先判斷用戶是否合法，然後輸入密碼，判斷密碼是否正確，如果輸入三次錯誤密碼，則自動跳出。否則輸出用戶error

#!/usr/bin/python
import getpass
#coding=utf-8
user = "root"
passwd = "westos"
username = raw_input("please input the username:")
if username == user:
    password = getpass.getpass("please input the password:")
    if password == passwd:
        print "login success"
    else:
        password = getpass.getpass("please input the password again:")
        if password == passwd:
                    print "login success"
         else:
                password = getpass.getpass("please input the password third:")
            if password == passwd:
                        print "login success"
            else:
                    print "you have no chance"
else:    
    print "username error"