def query_user_data(self, email):
    """ Searches through our cache or queries the UserAppServer for the data it
    stores for the given user.

    Args:
      email: A str that contains the e-mail address for the user whose
        information we want to retrieve.
    Returns:
      A str containing the user's data, or the empty string if their data could
      not be retrieved.
    """
    if self.cache['query_user_data'] in email:
      return self.cache['query_user_data'][email]

    try:
      user_data = self.get_uaserver().get_user_data(email, GLOBAL_SECRET_KEY)
      self.cache['query_user_data'][email] = user_data
      return user_data
    except Exception as err:
      logging.exception(err)
      return ''
dataset/ETHPy150Open AppScale/appscale/AppDashboard/lib/app_dashboard_helper.py/AppDashboardHelper.query_user_data/swapped operands of `in`