def post(self):
username = self.get_argument('u', None)
password = self.get_argument('p', '')
user = User.login(username, password)
if user:
session = self.create_user_session(user)
session.set(user=username)
return self.redirect('/')
# login error
self.render('login.html', error_message=u"用户名或密码错误", username=username, password=password)
