Python Without Fear

Praise for this book, Python Without Fear “This is really a great book. I wish I’d had it when I was learning Python.” –John M. Wargo, author of Apache Cordova 4 Programming Praise for the previous book in the series, C++ Without Fear “I’m in love with your C++ Without Fear book. It keeps me awake for hours during the night. Thanks to you, I got most of the idea in just a few hours.” –Laura Viral, graduate physics student at CERN and Istanbul, Turkey “It’s hard to tell where I began and ended with your book. I felt like I woke up and literally knew how to write C++ code. I can’t overstate the confidence you gave me.” – Danny Grady, senior programmer/analyst at a Fortune 500 Company Whether you’re new to programming or moving from another language, Python Without Fear will quickly make you productive! Brian Overland’s unique approach to Python includes: Taking you by the hand while teaching topics from the very basics to intermediate and advanced features of Python Teaching by examples that are explained line by line Heavy emphasis on examples that are fun and useful, including games, graphics, database applications, file storage, puzzles, and more! How to think “Pythonically” and avoid common “gotchas” Register your product at informit.com/register for convenient access to downloads, updates, and/or corrections as they become available.

Table of Contents:
Preface xvii Acknowledgments xxi Author Bio xxiii Chapter 1: Meet the Python 1 A Brief History of Python 1 How Python Is Different 2 How This Book Works 3 Installing Python 4 Begin Using Python with IDLE 6 Correcting Mistakes from Within IDLE 6 Dealing with Ends of Lines 7 Additional Help: Online Sources 8 Chapter 2: A Python Safari: Numbers 9 Python and Numbers 9 Python and Floating-Point Numbers 14 Assigning Numbers to Variables 17 Variable-Naming Conventions in This Book 23 Some Python Shortcuts 23 Chapter 2 Summary 26 Chapter 3: Your First Programs 29 Temperatures Rising? 29 Putting in a Print Message 35 Syntax Summaries 36 Getting String Input 41 Getting Numeric Input 43 Formatted Output String 46 Chapter 3 Summary 50 Chapter 4: Decisions and Looping 53 Decisions Inside a Computer Program 53 Conditional and Boolean Operators 55 The if, elif, and else Keywords 56 while: Looping the Loop 60 “Give Me a break” Statement 70 Chapter 4 Summary 75 Chapter 5: Python Lists 77 The Python Way: The World Is Made of Collections 77 Processing Lists with for 80 Modifying Elements with for (You Can't!) 82 Indexing and Slicing 85 Copying Data to Slices 88 Ranges 89 List Functions and the in Keyword 97 Chapter 5 Summary 99 Chapter 6: List Comprehension and Enumeration 101 Indexes and the enumerate Function 101 The Format String Method Revisited 103 Simple List Comprehension 106 “Two-Dimensional” List Comprehension 112 List Comprehension with Conditional 114 Chapter 6 Summary 123 Chapter 7: Python Strings 125 Creating a String with Quote Marks 125 Indexing and “Slicing” 127 String/Number Conversions 130 Stripping for Fun and Profit 135 Let’s Split: The split Method 138 Building Strings with Concatenation (+) 139 The join Method 143 Chapter 7 Summary 144 Chapter 8: Single-Character Ops 147 Naming Conventions in This Chapter 147 Accessing Individual Characters (A Review) 148 Getting Help with String Methods 148 Testing Uppercase vs. Lowercase 149 Converting Case of Letters 150 Testing for Palindromes 151 Converting to ASCII Code 159 Converting ASCII to Character 160 Chapter 8 Summary 166 Chapter 9: Advanced Function Techniques 167 Multiple Arguments 167 Returning More Than One Value 168 Arguments by Name 173 Default Arguments 174 Importing Functions from Modules 178 Chapter 9 Summary 185 Chapter 10: Local and Global Variables 187 Local Variables, What Are They Good For? 187 Locals vs. Globals 188 Introducing the global Keyword 190 The Python “Local Variable Trap” 190 Chapter 10 Summary 204 Chapter 11: File Ops 207 Text Files vs. Binary Files 207 The Op System (os) Module 208 Open a File 211 Let’s Write a Text File 213 Read a Text File 216 Files and Exception Handling 217 Other File Modes 223 Chapter 11 Summary 224 Chapter 12: Dictionaries and Sets 227 Why Do We Need Dictionaries, Ms. Librarian? 227 Adding and Changing Key-Value Pairs 229 Accessing Values 230 Searching for Keys 231 Converting Dictionaries to Lists 235 All About Sets 241 Operations on Sets 242 Chapter 12 Summary 246 Chapter 13: Matrixes: 2-D Lists 249 Simple Matrixes 249 Accessing Elements 250 Irregular Matrixes and Length of a Row 251 Multiplication (*) and Lists 252 The Python Matrix Problem 253 How to Create N*M Matrixes: The Solution 254 How to Rotate a Matrix 261 Chapter 13 Summary 268 Chapter 14: Winning at Tic-Tac-Toe 271 Design of a Tic-Tac-Toe Board 271 Plan of This Chapter 273 Python One-Line if/else 274 The count Method for Lists 279 Introducing the Computer Player 285 Chapter 14 Summary 294 Chapter 15: Classes and Objects I 295 What’s an Object? 295 Classes in Python 296 The All-Important _ _init_ Method 301 Design for a Database Class 303 Defining Other Methods 309 Design for a Point3D Class 310 Point3D Class and Default Arguments 312 Three-Dimensional Tic-Tac-Toe 312 Chapter 15 Summary 318 Chapter 16: Classes and Objects II 321 Getting Help from Doc Strings 321 Function Typing and “Overloading” 323 Variable-Length Argument Lists 326 Inheritance 331 The Fraction Class 333 Class Variables and Methods 337 Instance Variables as “Default” Values 339 Chapter 16 Summary 344 Chapter 17: Conway’s Game of Life 347 Game of Life: The Rules of the Game 348 Generating the Neighbor Count 350 Design of the Program 352 Moving the Matrix Class to a Module 354 The Famous Slider Pattern 358 Chapter 17 Summary 364 Chapter 18: Advanced Pythonic Techniques 367 Generators 367 Exploiting the Power of Generators 369 Properties 375 Decorators: Functions Enclosing Other Functions 382 Python Decoration 385 Chapter 18 Summary 389 Appendix A: Python Operator Precedence Table 391 Appendix B: Summary of Most Important Formatting Rules for Python 3.0 393 1. Formatting Ordinary Text 393 2. Formatting Arguments 393 3. Specifying Order of Arguments 393 4. Right Justification Within Field of Size N 394 5. Left Justification Within Field of Size N 394 6. Truncation: Limit Size of Print Field 394 7. Combined Truncation and Justification 395 8. Length and Precision of Floating-Point Numbers 395 9. The Padding Character 395 Appendix C: Glossary 397 Index 407

About the Author :
Brian Overland is a textbook author, sometime actor, programmer, film reviewer, and novelist. He has been professionally programming with the C family of languages since the early 1980s and spent 10 years at Microsoft, first as a software tester and then as programmer/writer, manager, and project lead. Almost unique among programmers, he is an award-winning writer deeply committed to teaching and simplifying advanced concepts.