LOL a .py program is a module, you can import it: if it is in the sys.path (import modulename). if it sits in a directory that is in the sys.path and the directory also has a __init__.py file (import dirname.modulename / from dirname import modulname). if there is a modulename.pth file in the sys.path containing the path to your .py file. (the current dir is always in the sys.path).
if you want to install your module (copy it under the site-packages dir), then you should use distutils module and create a setup.py script the compiled bytecode (.pyc file) is always automatically generated -- http://mail.python.org/mailman/listinfo/python-list