Logging in a user, and using cookies

postlogin.py

def post(self):
  user = self.get_argument("username")
  pwd = self.get_argument("password")
  login_info = self.db.logins.find_one({'$or' : [{'username': user.lower() }, {'email': user }]})
  if login_info is not None and bcrypt.hashpw(pwd, login_info['pwd_hash']) == login_info['pwd_hash']:
    user = self.db.users.find_one({"user_id": login_info['user_id']})
    self.set_secure_cookie(options.cookie_user, pickle.dumps(user))
    self.redirect(self.get_argument("next","/"))
  else:
    self.set_secure_cookie(options.cookie_alerts, pickle.dumps([{'content': "Bad login", 'level': 'error'}]))
    self.redirect("/{0}?next={1}".format(options.login_url,xhtml_escape(self.get_argument("next",""))))