使用Google App Engine python库验证Google Maps Engine API

Question

我希望Google App Engine python后端使用Google Maps Engine服务。这是我的代码片段：

import os
import urllib
import webapp2
import jinja2

from apiclient import discovery
import httplib2 
from oauth2client.appengine import OAuth2Decorator

decorator = OAuth2Decorator(
    client_id='<MY CLIENT ID>',
    client_secret='<MY CLIENT SECRET>',
    scope='https://www.googleapis.com/auth/mapsengine.readonly')

service = discovery.build('mapsengine', 'v1')

JINJA_ENVIRONMENT = jinja2.Environment(
    loader=jinja2.FileSystemLoader(os.path.dirname(__file__)),
    extensions=['jinja2.ext.autoescape'],
    autoescape=True)


class PrintHandler(webapp2.RequestHandler):
    def render_response(self, **kwargs):
        template = JINJA_ENVIRONMENT.get_template('report.html')
        self.response.write(template.render(**kwargs))

    @decorator.oauth_aware
    def post(self):
        if decorator.has_credentials():
            request = service.tables().features().list(id='<TABLE ID>')
            if request is not None:
                response = request.execute(decorator.http())
                self.render_response(features=response['features'])         
        else:
            url = decorator.authorize_url()
            self.render_response(authorize_url=url)

app = webapp2.WSGIApplication([
    ('/', PrintHandler),
    (decorator.callback_path, decorator.callback_handler())
], debug=True)

看起来上面的脚本没有任何错误，但没有返回任何信息。我已经通过https://developers.google.com/apis-explorer/#p/mapsengine/v1/中的oauth测试了请求，并且成功了。

有谁知道如何解决这个问题？

谢谢！