DiP3 is a good book, if you are already familiar with Python. It's not for newbies. In fact, when I didn't know Python I disliked DiP3 to the point of making rude and ignorant comments about it on public forums. Now that I have a humble portion of Python, I like the book and refer to it often. Mark Pilgrim has an engaging style, too. I always appreciate a little style.
If you are looking for an intro book, go with Zed Shaw's "Learn Python the Hard Way." There's another guy with lots of style.