PythonPath is a list of directories Python goes through to search for modules and files. All you need to know, you find at ​http://docs.python.org/install/index.html#modifying-python-s-search-path.

This is considered a very practical approach if you would like to have your apps outside the project directory.

How do you append directories to your Python path?

import sys
sys.path.append("/home/me/myapps")