Christopher Phillips is an educator, a freelance writer, and the founder of the non-profit Society for Philosophical Inquiry.Mark Lutz is a leading Python trainer, the author of Python's earliest and best-selling texts, and a pioneering figure in the Python world. Mark is the author of the three O'Reilly books: Learning Python, Programming Python, and Python Pocket Reference, all currently in fourth or fifth editions. He has been using and promoting Python since 1992, started writing Python books in 1995, and began teaching Python classes in 1997. As of Spring 2013, Mark has instructed 260 Python training sessions, taught roughly 4,000 students in live classes, and written Python books that have sold 400,000 units and been translated to at least a dozen languages. Together, his two decades of Python efforts have helped to establish it as one of the most widely used programming languages in the world today. In addition, Mark has been in the software field for 30 years. He holds BS and MS degrees in computer science from the University of Wisconsin where he explored implementations of the Prolog language, and over his career has worked as a professional software developer on compilers, programming tools, scripting applications, and assorted client/server systems. Mark maintains a training website ( http://learning-python.com ) and an additional book support site on the Web ( http://www.rmi.net/~lutz ).