[mattyb]

This looks like an approved translation to me:

http://learncodethehardway.org/

Also, from the linked page:

The prose in this translation is nearly 100% identical to the Python version with the exception of a few paragraphs that have been modified to be relevant to Ruby. All of the code exercises and required libraries have been completely adapted for Ruby. In other words, Zed did all the really hard work.