Program Arcade Games

Transcription

1 Program Arcade Games With Python and Pygame Fourth Edition Paul Vincent Craven

2 Program Arcade Games: With Python and Pygame, Fourth Edition Copyright 2016 by Paul Vincent Craven This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher s location, in its current version, and permission for use must always be obtained from Springer. Permissions for use may be obtained through RightsLink at the Copyright Clearance Center. Violations are liable to prosecution under the respective Copyright Law. ISBN-13 (pbk): ISBN-13 (electronic): Trademarked names, logos, and images may appear in this book. Rather than use a trademark symbol with every occurrence of a trademarked name, logo, or image we use the names, logos, and images only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein. Managing Director: Welmoed Spahr Lead Editor: Steve Anglin Editorial Board: Steve Anglin, Pramila Balan, Louise Corrigan, Jonathan Gennick, Robert Hutchinson, Celestin Suresh John, Michelle Lowman, James Markham, Susan McDermott, Matthew Moodie, Jeffrey Pepper, Douglas Pundick, Ben Renow-Clarke, Gwenan Spearing Coordinating Editor: Mark Powers Copy Editor: Karen Jameson Compositor: SPi Global Indexer: SPi Global Artist: SPi Global Distributed to the book trade worldwide by Springer Science+Business Media New York, 233 Spring Street, 6th Floor, New York, NY Phone SPRINGER, fax (201) , orders-ny@springer-sbm.com, or visit Apress Media, LLC is a California LLC and the sole member (owner) is Springer Science + Business Media Finance Inc (SSBM Finance Inc). SSBM Finance Inc is a Delaware corporation For information on translations, please rights@apress.com, or visit Apress and friends of ED books may be purchased in bulk for academic, corporate, or promotional use. ebook versions and licenses are also available for most titles. For more information, reference our Special Bulk Sales ebook Licensing web page at Any source code or other supplementary materials referenced by the author in this text is available to readers at For detailed information about how to locate your book s source code, go to Readers can also access source code at SpringerLink in the Supplementary Material section for each chapter.

3 This book is dedicated to everyone who loves to learn.

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5 Contents at a Glance About the Author...xix Introduction...xxi Chapter 1: Before Getting Started... 1 Chapter 2: Create a Custom Calculator Chapter 3: What Is a Computer Language? Chapter 4: Quiz Games and If Statements Chapter 5: Guessing Games with Random Numbers and Loops Chapter 6: Introduction to Graphics Chapter 7: Back to Looping Chapter 8: Introduction to Lists Chapter 9: Introduction to Animation Chapter 10: Functions Chapter 11: Controllers and Graphics Chapter 12: Bitmapped Graphics and Sound Chapter 13: Introduction to Classes Chapter 14: Introduction to Sprites Chapter 15: Libraries and Modules Chapter 16: Searching Chapter 17: Array-Backed Grids v

6 Contents at a Glance Chapter 18: Sorting Chapter 19: Exceptions Chapter 20: Recursion Chapter 21: Formatting Chapter 22: Exercises Index vi

7 Contents About the Author...xix Introduction...xxi Chapter 1: Before Getting Started... 1 Installing and Starting Python... 1 Windows Installation... 1 Mac Installation... 3 Unix Installation... 6 Optional Wing IDE... 7 Viewing File Extensions... 9 Learn to Make Games and Get Paid... 9 Get the Most from This Book Send Feedback Chapter 2: Create a Custom Calculator Printing Printing Text Printing Results of Expressions Printing Multiple Items Escape Codes Comments Assignment Operators Variables Operators Operator Spacing vii

8 Contents Order of Operations Trig Functions Custom Equation Calculators Review Multiple Choice Quiz Short Answer Worksheet...28 Exercise Chapter 3: What Is a Computer Language? Short History of Programming Review Multiple Choice Quiz Short Answer Worksheet...40 Exercise Chapter 4: Quiz Games and If Statements Basic Comparisons Indentation Using And/Or Boolean Variables Else and Else If Text Comparisons Multiple Text Possibilities Case Insensitive Comparisons Example if Statements Review Multiple Choice Quiz Short Answer Worksheet...55 Exercise viii

9 Contents Chapter 5: Guessing Games with Random Numbers and Loops for Loops Counting by Numbers Other Than One Nesting Loops Keeping a Running Total Example for Loops while Loops Using Increment Operators Looping Until User Wants to Quit Common Problems with while Loops Example while Loops Random Numbers The randrange Function The random Function Review Multiple Choice Quiz Short Answer Worksheet...78 Exercise Chapter 6: Introduction to Graphics Computer Coordinate Systems Pygame Library Colors Open a Window Interacting with the User The Event Processing Loop Processing Each Frame Ending the Program Clearing the Screen ix

10 Contents Flipping the Screen Open a Blank Window Drawing Introduction Drawing Lines Drawing Lines with Loops and Offsets Drawing a Rectangle Drawing an Ellipse Drawing an Arc Drawing a Polygon Drawing Text Full Program Listing Review Multiple Choice Quiz Short Answer Worksheet Exercise Chapter 7: Back to Looping Print Statement End Characters Advanced Looping Problems Review Multiple Choice Quiz Short Answer Worksheet Exercise Chapter 8: Introduction to Lists Working with Lists Iterating through a List Adding to a List Summing or Modifying a List Slicing Strings x

11 Contents Secret Codes Associative Arrays Review Multiple Choice Quiz Short Answer Worksheet Exercise Chapter 9: Introduction to Animation Animating Snow Code Explanation Full Program Listing D Animation Review Multiple Choice Quiz Short Answer Worksheet Exercise Chapter 10: Functions Function Parameters Returning and Capturing Values Returning Values Capturing Returned Values Improving the volume_cylinder Example Documenting Functions Variable Scope Pass-by-copy Functions Calling Functions Main Functions and Globals Short Examples Mudball Game Example xi

12 Contents Review Multiple Choice Quiz Short Answer Worksheet Correcting Code Exercise Chapter 11: Controllers and Graphics Mouse Keyboard Game Controller Review Multiple Choice Quiz Short Answer Worksheet Exercise Chapter 12: Bitmapped Graphics and Sound Storing the Program in a Folder Setting a Background Image Moving an Image Sounds Full Listing Review Multiple Choice Quiz Short Answer Worksheet Exercise Chapter 13: Introduction to Classes Why Learn About Classes? Defining and Creating Simple Classes Adding Methods to Classes Example: Ball Class xii

13 Contents References Functions and References Review Questions Constructors Avoid This Mistake Review Questions Inheritance Is-A and Has-A Relationships Static Variables vs. Instance Variables Instance Variables Hiding Static Variables Review Multiple Choice Quiz Short Answer Worksheet Exercise Chapter 14: Introduction to Sprites Basic Sprites and Collisions Moving Sprites The Game Class Other Examples Shooting things Walls Platforms Snake/Centipede Using Sprite Sheets Review Multiple Choice Quiz Exercise xiii

14 Contents Chapter 15: Libraries and Modules xiv Why Create a Library? Creating Your Own Module/Library File: Namespace Third Party Libraries Review Multiple Choice Quiz Short Answer Worksheet Exercise Chapter 16: Searching Reading from a File Reading into an Array Linear Search Linear Search Algorithm Variations on the Linear Search Does at Least One Item Have a Property? Do All Items Have a Property? Create a List with All Items Matching a Property Binary Search Review Multiple Choice Quiz Short Answer Worksheet Linear Search Review Binary Search Review Challenge Question Exercise Chapter 17: Array-Backed Grids Application Drawing the Grid Populating the Grid Final Program

15 Contents Review Multiple Choice Quiz Short Answer Worksheet Chapter 18: Sorting Swapping Values Selection Sort Insertion Sort Review Multiple Choice Quiz Short Answer Worksheet Chapter 19: Exceptions Vocabulary Exception Handling Example: Saving High Score Exception Objects Exception Generating Proper Exception Use Review Multiple Choice Quiz Short Answer Worksheet Chapter 20: Recursion Where Is Recursion Used? How Is Recursion Coded? Controlling Recursion Depth Recursion Factorial Calculation Recursive Rectangles Fractals xv

16 Contents Recursive Binary Search Review Short Answer Worksheet Chapter 21: Formatting Decimal Numbers Strings Leading Zeros Floating-Point Numbers Printing Dollars and Cents Use in Pygame Review Short Answer Worksheet Chapter 22: Exercises Exercise 1: Custom Calculators Program A Program B Program C Exercise 2: Create-a-Quiz Description Example Run Exercise 3: Camel Description of the Camel Game Sample Run of Camel Programming Guide Hints Exercise 4: Create-a-Picture Description xvi

17 Contents Exercise 5: Loopy Lab Part Part Part Part Exercise 6: Adventure! Description of the Adventure Game Sample Run Creating Your Dungeon Step-by-step Instructions Exercise 7: Animation Requirements Exercise 8: Functions Exercise 9: User Control Exercise 10: Bitmapped Graphics and User Control Exercise 11: Classes and Graphics Instructions Exercise 12: Sprite Collecting Exercise 13: Sprite Moving Exercise 14: Spell Check Requirements Steps to Complete: Example Run Exercise 15: Final Exercise Video Game Option Text Adventure Option Index xvii

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19 About the Author Paul Vincent Craven is a Computer Science professor at Simpson College in Indianola, Iowa. He worked in the IT industry for several years before switching to teaching full-time. He has a Ph.D. from the University of Idaho, a M.S. from Missouri University of Science and Technology, and B.A. from Simpson College. xix

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21 Introduction It all started in 1983 when my dad, who was also a teacher, bought an Apple //e computer for our use at home. Since it was to be dad s computer for educational purposes only, my brother and I were not allowed to purchase any games. So, at the local library I found two programming books by David H. Ahl: BASIC Computer Games and More BASIC Computer Games. These books had code I could use to type in and run my own games. This was the beginning of my creative outlet with computers. As a computer science professor, I have found getting other people to program their own games as a great way to foster interest in computer science. Unfortunately, back when I started teaching students this way, the type of book I started with in the 1980s did not seem to be available any longer. I wanted to help others learn to program the same way I started. To provide a textbook for my students, I began to write my own programming book. I started the website ProgramArcadeGames.com in The book you have in your hand morphed from the materials on that website and from student input from my beginning computer programming classes. I would like to acknowledge and thank everyone who took time to give feedback, no matter how large or small. This book is the product of hundreds of students I have worked with personally, and the feedback of hundreds of people on-line. I continue to develop the website and use this book to share my love of programming with others. xxi