Test-Driven Web Development With Python, the book.
License
The sources for this book are published under the Creative Commons Attribution Non-Commercial No-Derivs license (CC-BY-NC-ND).
I wouldn't recommend using this version to read the book. Head over to obeythetestinggoat.com when you can access a nicely formatted version of the full thing, still free and under CC license. And you'll also be able to buy an ebook or print version if you feel like it.
These sources are being made available for the purposes of curiosity (others writing books may be interested in the test suite for example) and collaboration (typo-fixes by pull request are very much encouraged).