Many of my books started as open source webpages, containing material that I wanted available for my lectures. And since Python is the most elegant and powerful programming language I know, I developed the respective source code in Python. When few other people contributed, I decided the best way to contribute to the amazingly helpful and friendly Python community is to publish these materials as books with a well-known, international publisher.
Statistics
My first effort to publish my statistics notes were turned down. But when Springer realized a) how popular Python has become, and b) that at the time there were few statistics books available that used Python, they decided to give me a chance anyway. And to my very big surprise, these books have been more successful than most or all of my research activities. Ignoring the Japanese and Chinese translations, up to now they have been downloaded > 350'000 times ...
Signal Analysis
Personally, I think this is my favorite book. When I developed code for signal analysis, the mathematical background of many algorithms (linear-time-invariant filters, splines, Fourier & Laplace transformations, ...) was unclear to me. In this book I tried to present things in such a way that they would have been most helpful to me when I first got introduced to those algorithms.
3D Kinematics
My first monograph! At the time of writing, I thought I would know more about quaternions and 3d-kinematics than many other people. And since inertial sensors are by now found in almost every electronic device, I thought that this book would be interesting to a lot of people. Ironically, it turned out to be the least popular of my books involving companion Python code.
Three-dimensional kinematic principles of eye-, head-, and limb movements
This book (published 1997) contains the conference proceedings of a conference that Michael Fetter, Hubert Misslisch, Douglas Tweed, and I organized in Tübingen.
Wikibook: Sensory Systems
This is not a book in the classical sense. If you have not worked with Wikibooks yet: they are open-source textbooks. This is in contrast to Wikipedia, which is an open source encyclopedia.
Thus this Wikibook on Sensory Systems was not only written by me. Starting with my lecture material for my course Computer Simulations of Sensory Systems which I held for many years at the ETH Zurich, Switzerland, many students contributed new articles, or translated existing articles into their own language. This way the wikibook is available (at least in parts) not only in English, but also in Chinese, Bulgarian, Greek, German, Spanish, French, Italian, and Norwegian. Check it out. I really think it is brilliant, and I wanted to thank all the students who made valuable contributions to it - Thanks a lot!