Task

Want to run both java and python by using the same application
(Note: this really only makes sense if you want to use common services such as datastore, memcache, queue, etc.; if not just deploy them as separate applications (doubles your quota) and communicate between them by using web services).

Solution

You can simply deploy them to different versions.  Note versions don't have to be numeric.  You can deploy your java code to version "java" and the corresponding url will be http://java.latest.YourApp.appspot.com ; and deploy your python to http://py.latest.YourApp.appspot.com by using version "py"

You can let java and python versions communicate between each other by using JSON (more precisely JSONP [for cross site requests]) http://code.google.com/webtoolkit/tutorials/1.6/Xsite.html

Using GWT also makes this job somewhat easier

Keywords

gae app same both java python simultaneously java and python both java and python app id appid together google app engine gwt