I am happy to announce the third edition of Think Python, which will be published by O’Reilly Media later this year.

You can read the online version of the book here. I’ve posted the Preface and the first four chapters — more on the way soon!

You can read the Early Release and pre-order from O’Reilly, or pre-order the third edition on Amazon.

Here is an excerpt from the Preface that explains…

What’s new in the third edition?

The biggest changes in this edition were driven by two new technologies — Jupyter notebooks and virtual assistants.

Each chapter of this book is a Jupyter notebook, which is a document that contains both ordinary text and code. For me, that makes it easier to write the code, test it, and keep it consistent with the text. For readers, it means you can run the code, modify it, and work on the exercises, all in one place.

The other big change is that I’ve added advice for working with virtual assistants like ChatGPT and using them to accelerate your learning. When the previous edition of this book was published in 2016, the predecessors of these tools were far less useful and most people were unaware of them. Now they are a standard tool for software engineering, and I think they will be a transformational tool for learning to program — and learning a lot of other things, too.

The other changes in the book were motivated by my regrets about the second edition.

The first is that I did not emphasize software testing. That was already a regrettable omission in 2016, but with the advent of virtual assistants, automated testing has become even more important. So this edition presents Python’s most widely-used testing tools, doctest and unittest, and includes several exercises where you can practice working with them.

My other regret is that the exercises in the second edition were uneven — some were more interesting than others and some were too hard. Moving to Jupyter notebooks helped me develop and test a more engaging and effective sequence of exercises.

In this revision, the sequence of topics is almost the same, but I rearranged a few of the chapters and compressed two short chapters into one. Also, I expanded the coverage of strings to include regular expressions.

A few chapters use turtle graphics. In previous editions, I used Python’s turtle module, but unfortunately it doesn’t work in Jupyter notebooks. So I replaced it with a new turtle module that should be easier to use. Here’s what it looks like in the notebooks.

Finally, I rewrote a substantial fraction of the text, clarifying places that needed it and cutting back in places where I was not as concise as I could be.

I am very proud of this new edition — I hope you like it!