Python Without Fear

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.

• Preface xviiAcknowledgments xxiAuthor Bio xxiiiChapter 1: Meet the Python 1A Brief History of Python 1How Python Is Different 2How This Book Works 3Installing Python 4Begin Using Python with IDLE 6Correcting Mistakes from Within IDLE 6Dealing with Ends of Lines 7Additional Help: Online Sources 8Chapter 2: A Python Safari: Numbers 9Python and Numbers 9Python and Floating-Point Numbers 14Assigning Numbers to Variables 17Variable-Naming Conventions in This Book 23Some Python Shortcuts 23Chapter 2 Summary 26Chapter 3: Your First Programs 29Temperatures Rising? 29Putting in a Print Message 35Syntax Summaries 36Getting String Input 41Getting Numeric Input 43Formatted Output String 46Chapter 3 Summary 50Chapter 4: Decisions and Looping 53Decisions Inside a Computer Program 53Conditional and Boolean Operators 55The if, elif, and else Keywords 56while: Looping the Loop 60“Give Me a break” Statement 70Chapter 4 Summary 75Chapter 5: Python Lists 77The Python Way: The World Is Made of Collections 77Processing Lists with for 80Modifying Elements with for (You Can't!) 82Indexing and Slicing 85Copying Data to Slices 88Ranges 89List Functions and the in Keyword 97Chapter 5 Summary 99Chapter 6: List Comprehension and Enumeration 101Indexes and the enumerate Function 101The Format String Method Revisited 103Simple List Comprehension 106“Two-Dimensional” List Comprehension 112List Comprehension with Conditional 114Chapter 6 Summary 123Chapter 7: Python Strings 125Creating a String with Quote Marks 125Indexing and “Slicing” 127String/Number Conversions 130Stripping for Fun and Profit 135Let’s Split: The split Method 138Building Strings with Concatenation (+) 139The join Method 143Chapter 7 Summary 144Chapter 8: Single-Character Ops 147Naming Conventions in This Chapter 147Accessing Individual Characters (A Review) 148Getting Help with String Methods 148Testing Uppercase vs. Lowercase 149Converting Case of Letters 150Testing for Palindromes 151Converting to ASCII Code 159Converting ASCII to Character 160Chapter 8 Summary 166Chapter 9: Advanced Function Techniques 167Multiple Arguments 167Returning More Than One Value 168Arguments by Name 173Default Arguments 174Importing Functions from Modules 178Chapter 9 Summary 185Chapter 10: Local and Global Variables 187Local Variables, What Are They Good For? 187Locals vs. Globals 188Introducing the global Keyword 190The Python “Local Variable Trap” 190Chapter 10 Summary 204Chapter 11: File Ops 207Text Files vs. Binary Files 207The Op System (os) Module 208Open a File 211Let’s Write a Text File 213Read a Text File 216Files and Exception Handling 217Other File Modes 223Chapter 11 Summary 224Chapter 12: Dictionaries and Sets 227Why Do We Need Dictionaries, Ms. Librarian? 227Adding and Changing Key-Value Pairs 229Accessing Values 230Searching for Keys 231Converting Dictionaries to Lists 235All About Sets 241Operations on Sets 242Chapter 12 Summary 246Chapter 13: Matrixes: 2-D Lists 249Simple Matrixes 249Accessing Elements 250Irregular Matrixes and Length of a Row 251Multiplication (*) and Lists 252The Python Matrix Problem 253How to Create N*M Matrixes: The Solution 254How to Rotate a Matrix 261Chapter 13 Summary 268Chapter 14: Winning at Tic-Tac-Toe 271Design of a Tic-Tac-Toe Board 271Plan of This Chapter 273Python One-Line if/else 274The count Method for Lists 279Introducing the Computer Player 285Chapter 14 Summary 294Chapter 15: Classes and Objects I 295What’s an Object? 295Classes in Python 296The All-Important _ _init_ Method 301Design for a Database Class 303Defining Other Methods 309Design for a Point3D Class 310Point3D Class and Default Arguments 312Three-Dimensional Tic-Tac-Toe 312Chapter 15 Summary 318Chapter 16: Classes and Objects II 321Getting Help from Doc Strings 321Function Typing and “Overloading” 323Variable-Length Argument Lists 326Inheritance 331The Fraction Class 333Class Variables and Methods 337Instance Variables as “Default” Values 339Chapter 16 Summary 344Chapter 17: Conway’s Game of Life 347Game of Life: The Rules of the Game 348Generating the Neighbor Count 350Design of the Program 352Moving the Matrix Class to a Module 354The Famous Slider Pattern 358Chapter 17 Summary 364Chapter 18: Advanced Pythonic Techniques 367Generators 367Exploiting the Power of Generators 369Properties 375Decorators: Functions Enclosing Other Functions 382Python Decoration 385Chapter 18 Summary 389Appendix A: Python Operator Precedence Table 391Appendix B: Summary of Most Important Formatting Rules for Python 3.0 3931. Formatting Ordinary Text 3932. Formatting Arguments 3933. Specifying Order of Arguments 3934. Right Justification Within Field of Size N 3945. Left Justification Within Field of Size N 3946. Truncation: Limit Size of Print Field 3947. Combined Truncation and Justification 3958. Length and Precision of Floating-Point Numbers 3959. The Padding Character 395Appendix C: Glossary 397Index 407