For apps with a module entry point, make a stub: Some applications use a module as an entry point, for instance by having a __main__.py file that’s invoked when the module is imported.

Python eggs require site.py to be processed in order to do all the necessary setup. If that didn't happen, then adding the egg to sys.path won't work AFAIK. Due to PTH processing and the like ...

This post explains what a Python module is and how to use it to drastically extend the capabiltiies of your code. Plus: how to make your own!