How do you submit a form to an app engine python application without refreshing the sending page?
Sounds like you want to look into AJAX. The simplest way to do this is probably to use the ajax functions in one of the popular Javascript libraries, like jQuery.
As a newbie to app engine and python I can follow the examples given by Google and have created a python application with a template HTML page where I can enter data, submit it to the datastore and by reading back the data, just sent, recreate the sending page so I can continue adding data and store again.  However what I would like to do is submit the data, have it stored in the datastore without the sending page being refreshed. It seems like a waste of traffic to have all the data sent back again.