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]


How to get Selenium to wait for page load after a click

Getting Selenium to wait until the next page has fully loaded after you click on a link seems like it should be easy, but it's actually very hard to do reliably, but I think we may have cracked it. Read on!

Wed 03 September 2014 by Harry

Kent Beck on the limits of TDD

As part of the #isTDDDead discussions, Kent Beck had a pithy reflection on what the limits of TDD might be.

Tue 03 June 2014 by Harry

Book upgraded to Django 1.7!

I've just completed the process of upgrading the whole book to the Django 1.7 beta release. Migrations were the biggest change. They've meant a slight increase to the learning curve for chapters 5 & 6, but on the other hand I was able to drop the dedicated migrations chapter altogether!

Wed 02 April 2014 by Harry

How to log exceptions to stderr in Django

Django logging can be a little baffling. Here's an answer to the "how do I make django log all exceptions to the console?" question, which isn't necessarily obvious.

Thu 23 January 2014 by Harry

« Page 3 / 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.