I had high hopes for this book. It is well written and I very much appreciate the detail and dedication that went into it. I am only 4 chapters in, but I already have to say that this book was great for 3-4 years ago. The tools have improved so much since then that it needs a major rework. The biggest change: Down with doctest, up with ipython notebooks. I dislike the use of getopt and avoiding the initial configure of setup.py to allow python setup.py test is a bummer. I think a full mini project would be a better focus for a book like this. An now we have awesome and easy to use continuous integration (CI) tools like Travis-CI. It no longer matters if your full tests take 15 minutes to run. They always get run.
I am definitely learning from this book, but I have to do a lot of modifications of methods to apply them to my world.