About the book
I have been teaching programming for many years now. Since 2008, when I joined Tilburg University, the students I have been teaching programming to were mostly not computer science students. Somewhat to my surprise, I found that there are many people for whom programming is an arcane topic. I had to rethink my approach to teaching programming to people for whom it does not come naturally at all.
I started out with only a handful of students in my Python programming class. This number rose sharply over the years, to about 100 students every year. I believe this is because students have started to realise that knowledge of computational techniques and programming has become a requirement for getting a good job. As the entry level of knowledge and abilities differs widely between the students, some of them have to spend much more time on a programming course than others. I had to come up with a way to allow all the students to learn, without wasting anybody's time.
My answer to this issue was building a course that students can do mostly through self-study. This proved to be a time-intensive project, but a very rewarding one, as many students responded enthusiastically to this approach. The huge advantage of using a self-study approach is that I do no longer need to worry whether everybody picks up everything that is contained in my oral lectures -- since I know that everything that students need to know is written down and can be studied at a speed that works for each individual student, I can reserve my lectures to answering questions and assisting students with writing code.
I personally believe that learning to program should be done in middle schools, to teenagers. The younger you are when you try to pick this up, the easier it will be. Python is a great language to teach teenagers, and here is a lot of good material available aimed at a novice crowd. Unfortunately, most of this material is in English, and not all teenagers are sufficiently fluent in that language to allow them to learn with it. In particular, I am regularly approached by Dutch youngesters who ask me what they can use to learn Python using the Dutch language, for which there are very sources available. I therefore decided to turn my Python course into a Dutch language book.
As my course already existed in English, I first created an English version of the book, which took no more than 2 weeks of time. Then I translated this book, over the course of several months, to Dutch. Both books are finished now, and are freely available from this website.