使用python包的本地副本而不是site-packages中安装的副本

I've installed a Python based package in my site-packages directory. However, I'm trying to learn how the code works so I'd like to hack it a bunch by putting in lots of print statements so I can understand what the code is doing. But at the end of the day I want a clean installation without all my hacks in it. I've installed a Python based package in my sit