I modified pubsubhubbub implementation. No longer original impl does not work, because it has no update from 2011.
https://github.com/ashphy/pubsubhubbub
My forked impl will works fine with Python 2.7 and Google App Engine for Python 1.8.9.
I’m unfamiliar with Python and GAE. Any improvements are welcome.
How to Run the servers
$ git clone https://code.google.com/p/pubsubhubbub/
Hub
$ dev_appserver.py hub
Publisher
$ dev_appserver.py --port=8081 --admin_port=8001 publisher
Subscriber
$ dev_appserver.py --port=8082 --admin_port=8002 subscriber
ashphy coding 