How does Python keep track of modules installed with eggs?

Question

If I have a module, foo, in Lib/site-packages, I can just import foo and it will work. However, when I install stuff from eggs, I get some

Answer 1

When you run easy_install it copies the egg into site-packages and puts the path to that egg on your sys.path variable. (Note that sys.path is not your PATH environment variable, it is constructed from PYTHONPATH and other environment variables. So the .egg file you install with easy_install gets put in some environment variable and python knows to add it to sys.path when the python interpreter starts).

To get blah.haha to work in your example, either run easy_install blah-4.0.1-py2.7-win32.egg and then you can import haha from within python, or just put the haha module directly in site-packages.