using namespace 'test' in app engine when it runs by dev server or is called with subdomain 'test.'

appengine_config.py

# -*- coding: utf-8 -*-
import os
from google.appengine.api import namespace_manager

def namespace_manager_default_namespace_for_request():
  if 'test' in os.environ['SERVER_NAME'] or 'Dev' in os.environ['SERVER_SOFTWARE']:
    return 'test'
  return namespace_manager.google_apps_namespace()