Dive Into Python is a free Python tutorial, written by Mark Pilgrim.
Dive Into Python book lives at http://diveintopython.org/. If you're reading it somewhere else, you may not have the latest version.
Permission is granted to copy, distribute, and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in Appendix G, GNU Free Documentation License.
The example programs in this book are free software; you can redistribute and/or modify them under the terms of the Python license as published by the Python Software Foundation. A copy of the license is included in Appendix H, Python license.