The Testing Goat

Obey the Testing Goat!

TDD for the Web, with Python, Selenium, Django, JavaScript and pals...

Test-Driven Development with Python, 2e, cover

The book

This is my book about Test-Driven-Development for web programming, published by the excellent O'Reilly Media.

There are a few ways you can read and support this book:

Obviously these are my favourite options! O'Reilly have been great, they deserve your support, and although I only get a small amount in royalties (about a dollar per sale if you're curious), it still pays for the occasional dinner out every month which I appreciate. Plus, real physical books are nice...

TIP: I don't recommend you use Google Play Books, or at least not their PDF version, it's horrible

Alternatively, or in the meantime, help yourself here! It's all free and CC-licenced (thanks O'Reilly!). I see this as a "try-before-you-buy" scheme, and I hope that if you enjoy it you'll buy a copy -- if not for yourself, then perhaps for a friend!

And do get in touch with comments, suggestions, corrections etc! [email protected]


A lovely review! "like sitting down to pair-program with the author"

Jason wrote a review of my book, saying things like: "I find far too many programming books compartmentalize the material, each section is separate and abstract. Rather, this book's strength is in the broad use and application of these tools. By the end of this book you won't be a master with these tools but you will have used them enough to build a good foundation for starting your own projects and into the habit of test, code, refactor, commit."

Mon 13 May 2013 by Harry

Day against DRM and this book's copyright

Not only does my book have no DRM, it also has a 10-year limit on copyright, and will be released online under creative commons in parallel to the print release

Fri 03 May 2013 by Harry

"TDD / Django tutorial: The Book!"

I'm thinking of adapting my TDD / Django tutorial into a full book on TDD for web apps. Here's my current proposed outline, and all the topics I'm thinking of covering, what do you think?

Sun 03 March 2013 by Harry

The next stage: writing a book

I've decided to try and develop this tutorial into an actual book on test-driven development for web apps. Have a look at the chapter outline I've posted as part 6:

Tue 08 January 2013 by Harry

« Page 4 / 4

Read the book

The book is available both for free and for money. It's all about TDD and Web programming. Read it here!

Reviews & Testimonials

"Hands down the best teaching book I've ever read""Even the first 4 chapters were worth the money""Oh my gosh! This book is outstanding""The testing goat is my new friend"Read more...


A selection of links and videos about TDD, not necessarily all mine, eg this tutorial at PyCon 2013, how to motivate coworkers to write unit tests, thoughts on Django's test tools, London-style TDD and more.

Old TDD / Django Tutorial

This is my old TDD tutorial, which follows along with the official Django tutorial, but with full TDD. It badly needs updating. Read the book instead!

Save the Testing Goat Campaign

The campaign page, preserved for history, which led to the glorious presence of the Testing Goat on the front of the book.