I purchased this book because it was required for online Python courses taught by the author. I have not found a better beginner Python book out there. Plus, now that I am a professional Python programmer, I find myself constantly referring to this book to clarify certain points and reinforce understanding of basic principles. (I may be a professional, but I'm still a rookie.) I've purchased a few fat, expensive Python programming books with animals on the cover, but these tend to collect dust. In short, I have a new-found appreciation for this book and how much work went in to writing it. Thanks, Professor Severance!