Preliminary Step: Scope and Environment
To get started, note that I'm not supplanting the steps found within the Google App Engine Getting Started tutorial, which is still the only coherent tutorial for Google App Engine development. If you're making use of my sequence, below, I assume that you're already running the development environment, based on instructions in the GAE tutorial.
Again I'm focussed on simply passing keys. This sequence will not develop code for editing, ownership, user authentication, sessions, sorting, timestamps, AJAX, exception handling, CSS, backups or any number of otherwise perfectly reasonable and necessary features. But, clearly, those tasks too can be broken into small sequences, "snippets" if you will, which could be applied in an additive fashion to any application derived from this article.
In this example I'm also using a very simple subset of Python, free of 'dunder' methods, and avoiding the Django helper. I want to limit the number of technical features I'm describing here, while allowing as broad a swath of programmers as possible to read it. Similar limits were placed on the tutorials produced by Google.
We'll call this List-Item sample application "Passing Keys", or "passingkeys" to GAE. It's hosted at passingkeys.appspot.com, with links to the source. The primary Python module is passingkeys.py .