sometimes it is useful to add a path to the Python path to find a module that you don't want to install system wide:

import os, sys

#add parent's parent directory to path to find module if not installed
sys.path.append(os.path.dirname(os.getcwd()))

This is especially useful for unit tests if the module is not installed system wide:
/c/templates/template_test.py


update the python path at the start of the dev_appserver.py script if you've installed python2.5 so that it is not the default python instance

sudo chmod 777 google_appengine/dev_appserver.py

#!/usr/bin/python2.5

also [2010.07.11 21:07:33]
having trouble getting things to run with stock build of 2.5
it at least launched with 2.6