In an effort to advance my python skills, I spent some time slowly pecking away at the puzzles on pythonchallenge. I got stuck on most of the challenges, and either had to search for a hint, or ask for help from a friend, or both. This latest one was particularly instructive, and it had to do with zipfiles. I thought I knew what zip files were. I have used them since grad school, for transferring folders via email, and for compression.