WARNING FOR NEW READERS: In fact, this book was written back one year ago, during 2015 Christmas break. TensorFlow captivated me and I wanted to share this knowledge with my students. Keep in mind when you read this book that it was based in an old TensorFlow release (tensorflow-0.5.0) and it is only suitable for introduction purpose. Current release (tensorflow-0.12.0) have many new and important features. No one ever believed this book was going to become such a great and successful help for many students and practitioners. Knowing this is an honor for me, thank you! But in my opinion now this book already has to give the witness to more current ones (based in tensorflow-0.12.0).