Copyright C2002 Allen Downey,Jeffrey Elkner,and Chris Meyers. Edited by Shannon Turlington and Lisa Cutler.Cover design by Rebecca Gimenez. Printing history: April 2002:First edition. August 2008:Second printing. Green Tea Press 1 Grove St. P.O.Box812901 Wellesley,MA 02482 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 the Invariant Sections being"Foreword,""Preface," and "Contributor List,"with no Front-Cover Texts,and with no Back-Cover Texts. A copy of the license is included in the appendix entitled "GNU Free Documentation License." The GNU Free Documentation License is available from www.gnu.org or by writing to the Free Software Foundation,Inc.,59 Temple Place,Suite 330,Boston,MA 02111-1307, USA. The original form of this book is ITEX source code.Compiling this ITEX source has the effect of generating a device-independent representation of a textbook,which can be converted to other formats and printed. The IATEX source for this book is available from http://www.thinkpython.com Publisher's Cataloging-in-Publication (provided by Quality Books,Inc.) Downey,Allen How to think like a computer scientist learning with Python /Allen Downey,Jeffrey Elkner,Chris Meyers.-1st ed. p.cm. Includes index. ISBN0-9716775-0-6 LCCN2002100618 1.Python (Computer program language)I.Elkner, Jeffrey.II.Meyers,Chris.III.Title QA76.73.P98D692002 005.133 QBI02-200031Copyright c 2002 Allen Downey, Jeffrey Elkner, and Chris Meyers. Edited by Shannon Turlington and Lisa Cutler. Cover design by Rebecca Gimenez. Printing history: April 2002: First edition. August 2008: Second printing. Green Tea Press 1 Grove St. P.O. Box 812901 Wellesley, MA 02482 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 the Invariant Sections being “Foreword,” “Preface,” and “Contributor List,” with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the appendix entitled “GNU Free Documentation License.” The GNU Free Documentation License is available from www.gnu.org or by writing to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA. The original form of this book is LATEX source code. Compiling this LATEX source has the effect of generating a device-independent representation of a textbook, which can be converted to other formats and printed. The LATEX source for this book is available from http://www.thinkpython.com Publisher’s Cataloging-in-Publication (provided by Quality Books, Inc.) Downey, Allen How to think like a computer scientist : learning with Python / Allen Downey, Jeffrey Elkner, Chris Meyers. – 1st ed. p. cm. Includes index. ISBN 0-9716775-0-6 LCCN 2002100618 1. Python (Computer program language) I. Elkner, Jeffrey. II. Meyers, Chris. III. Title QA76.73.P98D69 2002 005.13’3 QBI02-200031