Deleting data in local database:
dev_appserver.py —clear_datastore

Redirecting:
self.redirect("/" + forum.url, True) (on classes deriving from webapp.RequestHandler)

Starting app locally:
dev_appserver.py --port=9999 myapp where “myapp” is name of directory with your app (one that has app.yaml) e.g.: dev_appserver.py --port=9999 .

self.request.get("cancel") – get POST or GET params

self.request.path_info – url (e.g. /foo/bar)