To paraphrase the philosophy of the Free Software Foundation, this book is free like free speech, but not necessarily free like free pizza. It came about because of a collaboration that would not have been possible without the GNU Free Documentation License. So we would like to thank the Free Software Foundation for developing this license and, of course, making it available to us.
We would also like to thank the more than 100 sharp-eyed and thoughtful readers who have sent us suggestions and corrections over the past few years. In the spirit of free software, we decided to express our gratitude in the form of a contributor list. Unfortunately, this list is not complete, but we are doing our best to keep it up to date. It was also getting too large to include everyone who sends in a typo or two. You have our gratitude, and you have the personal satisfaction of making a book you found useful better for you and everyone else who uses it. New additions to the list for the 2nd edition will be those who have made on-going contributions.
If you have a chance to look through the list, you should realize that each person here has spared you and all subsequent readers from the confusion of a technical error or a less-than-transparent explanation, just by sending us a note.
Impossible as it may seem after so many corrections, there may still be errors in this book. If you should stumble across one, we hope you will take a minute to contact us. The email address is email@example.com . Substantial changes made due to your suggestions will add you to the next version of the contributor list (unless you ask to be omitted). Thank you!
An email from Mike MacHenry set me straight on tail recursion. He not only pointed out an error in the presentation, but suggested how to correct it.
It wasn’t until 5th Grade student Owen Davies came to me in a Saturday morning Python enrichment class and said he wanted to write the card game, Gin Rummy, in Python that I finally knew what I wanted to use as the case study for the object oriented programming chapters.
A special thanks to pioneering students in Jeff’s Python Programming class at GCTAA during the 2009-2010 school year: Safath Ahmed, Howard Batiste, Louis Elkner-Alfaro, and Rachel Hancock. Your continual and thoughtfull feedback led to changes in most of the chapters of the book. You set the standard for the active and engaged learners that will help make the new Governor’s Academy what it is to become. Thanks to you this is truly a student tested text.
Thanks in a similar vein to the students in Jeff’s Computer Science class at the HB-Woodlawn program during the 2007-2008 school year: James Crowley, Joshua Eddy, Eric Larson, Brian McGrail, and Iliana Vazuka.
Ammar Nabulsi sent in numerous corrections from Chapters 1 and 2.
Aldric Giacomoni pointed out an error in our definition of the Fibonacci sequence in Chapter 5.
Roger Sperberg sent in several spelling corrections and pointed out a twisted piece of logic in Chapter 3.
Adele Goldberg sat down with Jeff at PyCon 2007 and gave him a list of suggestions and corrections from throughout the book.
Ben Bruno sent in corrections for chapters 4, 5, 6, and 7.
Carl LaCombe pointed out that we incorrectly used the term commutative in chapter 6 where symmetric was the correct term.
Alessandro Montanile sent in corrections for errors in the code examples and text in chapters 3, 12, 15, 17, 18, 19, and 20.
Emanuele Rusconi found errors in chapters 4, 8, and 15.
Michael Vogt reported an indentation error in an example in chapter 6, and sent in a suggestion for improving the clarity of the shell vs. script section in chapter 1.
Lloyd Hugh Allen sent in a correction to Section 8.4.
Yvon Boulianne sent in a correction of a semantic error in Chapter 5.
Fred Bremmer submitted a correction in Section 2.1.
Jonah Cohen wrote the Perl scripts to convert the LaTeX source for this book into beautiful HTML.
Michael Conlon sent in a grammar correction in Chapter 2 and an improvement in style in Chapter 1, and he initiated discussion on the technical aspects of interpreters.
Benoit Girard sent in a correction to a humorous mistake in Section 5.6.
Courtney Gleason and Katherine Smith wrote horsebet.py, which was used as a case study in an earlier version of the book. Their program can now be found on the website.
Lee Harr submitted more corrections than we have room to list here, and indeed he should be listed as one of the principal editors of the text.
James Kaylin is a student using the text. He has submitted numerous corrections.
David Kershaw fixed the broken catTwice function in Section 3.10.
Eddie Lam has sent in numerous corrections to Chapters 1, 2, and 3. He also fixed the Makefile so that it creates an index the first time it is run and helped us set up a versioning scheme.
Man-Yong Lee sent in a correction to the example code in Section 2.4.
David Mayo pointed out that the word unconsciously in Chapter 1 needed to be changed to subconsciously .
Chris McAloon sent in several corrections to Sections 3.9 and 3.10.
Matthew J. Moelter has been a long-time contributor who sent in numerous corrections and suggestions to the book.
Simon Dicon Montford reported a missing function definition and several typos in Chapter 3. He also found errors in the increment function in Chapter 13.
John Ouzts corrected the definition of return value in Chapter 3.
Kevin Parks sent in valuable comments and suggestions as to how to improve the distribution of the book.
David Pool sent in a typo in the glossary of Chapter 1, as well as kind words of encouragement.
Michael Schmitt sent in a correction to the chapter on files and exceptions.
Robin Shaw pointed out an error in Section 13.1, where the printTime function was used in an example without being defined.
Paul Sleigh found an error in Chapter 7 and a bug in Jonah Cohen’s Perl script that generates HTML from LaTeX.
Craig T. Snydal is testing the text in a course at Drew University. He has contributed several valuable suggestions and corrections.
Ian Thomas and his students are using the text in a programming course. They are the first ones to test the chapters in the latter half of the book, and they have make numerous corrections and suggestions.
Keith Verheyden sent in a correction in Chapter 3.
Peter Winstanley let us know about a longstanding error in our Latin in Chapter 3.
Chris Wrobel made corrections to the code in the chapter on file I/O and exceptions.
Moshe Zadka has made invaluable contributions to this project. In addition to writing the first draft of the chapter on Dictionaries, he provided continual guidance in the early stages of the book.
Christoph Zwerschke sent several corrections and pedagogic suggestions, and explained the difference between gleich and selbe.
James Mayer sent us a whole slew of spelling and typographical errors, including two in the contributor list.
Hayden McAfee caught a potentially confusing inconsistency between two examples.
Angel Arnal is part of an international team of translators working on the Spanish version of the text. He has also found several errors in the English version.
Tauhidul Hoque and Lex Berezhny created the illustrations in Chapter 1 and improved many of the other illustrations.
Dr. Michele Alzetta caught an error in Chapter 8 and sent some interesting pedagogic comments and suggestions about Fibonacci and Old Maid.
Andy Mitchell caught a typo in Chapter 1 and a broken example in Chapter 2.
Kalin Harvey suggested a clarification in Chapter 7 and caught some typos.
Christopher P. Smith caught several typos and is helping us prepare to update the book for Python 2.2.
David Hutchins caught a typo in the Foreword.
Gregor Lingl is teaching Python at a high school in Vienna, Austria. He is working on a German translation of the book, and he caught a couple of bad errors in Chapter 5.
Julie Peters caught a typo in the Preface.