Well that is one of the things I don't like about Python. You can silently corrupt a namespace and have no idea about it until your code actually runs. This should fix the issue for now.
Made some small updates to the extent_test.py master script.
Created a top level script for fully automating the full extent test process (well, aside from data analysis).
Created another script to dump the raw extent sizes so that you can then calculate things like the standard deviation.
Adding fiemap testing scripts which includes the very handy python fiemap bindings I found on the intarwebz.