Julie Anderson - Python Programming in Context, 3rd Edition

World Headquarters
Jones & Bartlett Learning
5 Wall Street
Burlington, MA 01803
978-443-5000
www.jblearning.com

Jones & Bartlett Learning books and products are available through most bookstores and online booksellers. To contact Jones & Bartlett Learning directly, call 800-832-0034, fax 978-443-8000, or visit our website, www.jblearning.com.

Substantial discounts on bulk quantities of Jones & Bartlett Learning publications are available to corporations, professional associations, and other qualified organizations. For details and specific discount information, contact the special sales department at Jones & Bartlett Learning via the above contact information or send an email to .

Copyright 2021 by Jones & Bartlett Learning, LLC, an Ascend Learning Company

All rights reserved. No part of the material protected by this copyright may be reproduced or utilized in any form, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission from the copyright owner.

The content, statements, views, and opinions herein are the sole expression of the respective authors and not that of Jones & Bartlett Learning, LLC. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement or recommendation by Jones & Bartlett Learning, LLC, and such reference shall not be used for advertising or product endorsement purposes. All trademarks displayed are the trademarks of the parties noted herein. Python Programming in Context, Third Edition is an independent publication and has not been authorized, sponsored, or otherwise approved by the owners of the trademarks or service marks referenced in this product.

There may be images in this book that feature models; these models do not necessarily endorse, represent, or participate in the activities represented in the images. Any screenshots in this product are for educational and instructive purposes only. Any individuals and scenarios featured in the case studies throughout this product may be real or fictitious but are used for instructional purposes only.

17652-0

Production Credits
VP, Product Management: Amanda Martin
Director of Product Management: Laura Pagluica
Product Manager: Ned Hinman
Product Assistant: Melissa Duffy
Product Coordinator: Paula-Yuan Gregory
Project Specialist: John Fuller
Digital Products Manager: Jordan McKenzie
Digital Project Specialist: Angela Dooley
Marketing Manager: Michael Sullivan
Production Services Manager: Colleen Lamy
Product Fulfillment Manager: Wendy Kilborn
Composition: codeMantra U.S. LLC
Cover Design: Scott Moden
Text Design: Kristin E. Parker
Senior Media Development Editor: Shannon Sheehan
Rights Specialist: Rebecca Damon
Cover Image (Title Page, Part Opener, Chapter Opener): AF-studio/Gettyimages
Printing and Binding: LSC Communications
Cover Printing: LSC Communications

Library of Congress Cataloging-in-Publication Data
Names: Miller, Bradley N., author. | Ranum, David L., author. | Anderson, Julie, 1947- author.
Title: Python programming in context / Bradley N. Miller, David L. Ranum, Julie Anderson.
Description: Third edition. | Burlington, Massachusetts : Jones & Bartlett Learning, [2021] | Includes bibliographical references and index.
Identifiers: LCCN 2019013595 (print) | LCCN 2019018504 (ebook) | ISBN 9781284175585 (ebook) | ISBN 9781284176520
Subjects: LCSH: Python (Computer program language)
Classification: LCC QA76.73.P98 (ebook) | LCC QA76.73.P98 M544 2021 (print) | DDC 005.13/3dc23
LC record available at https://lccn.loc.gov/2019013595

6048

Printed in the United States of America
23 22 21 20 19 10 9 8 7 6 5 4 3 2 1

For my wife, Jane, and my children, Kaia and Joshua

BNM

For my wife, Brenda, and my three children, Kelsey, Hannah, and Rylea

DLR

For my husband, Tom, my children, Brian and Jon, my daughter-in-law, Silvia, and my grandchildren Suri, Ben, and Reyna

JAA

CONTENTS

PREFACE

Introduction

Computer science deals with people who have problems to solve. Algorithms help find the solutions to those problems. To be a computer scientist means first and foremost that you are a problem solver, capable of constructing algorithms either from scratch or by applying patterns from past experience.

The only way to be successful in learning computer science is through deliberate and incremental exposure to the fundamental ideas of the discipline. A beginning student of computer science needs practice to establish a thorough understanding of a concept before continuing on to the more complex parts of the curriculum. In addition, a beginner needs the opportunity to be successful and to gain confidence. As students progress through the introductory computer science sequence, we want them to focus on aspects of problem solving, algorithm development, and algorithm understanding.

In this text, we use Python as the programming language because it has a clean, simple syntax and an intuitive user environment. The basic collections are powerful, yet easy to use. The interactive nature of the language creates a place to test ideas without the need for a lot of coding. Finally, Python provides a textbook-like notation for representing algorithms, alleviating the need for an additional layer of pseudocode. This allows the illustration of many relevant, modern, and interesting problems that make use of algorithms.

Key Features

This text is designed to be a first course in computer science that focuses on problem solving, with language features being introduced as needed to solve the problem at hand. We have structured the text around problems of general interest, rather than a traditional language-element structure. Thus, you will not see chapter titles in this text like Loops and Conditionalsbut you will see chapter titles such as Planet Objects and Codes and Other Secrets.

Throughout the text, concepts are introduced using a spiral model. Because the syntax of Python is easy to learn, we can quickly introduce the basics of standard programming constructs. As students progress through the text, more of the details and background for these constructs are added to their toolbox. In this way, students are exposed to important computer science concepts at the point when those concepts are needed to solve a problem.

An illustration of how this spiral approach touches on a specific topic in different ways can be seen in our presentation of functions. Students begin to write functions with parameters in , students learn to write abstract methods.