Introduction to computing and programming in Python: a multimedia approach

Cover......Page 1
Title Page......Page 2
Copyright Page......Page 3
ACKNOWLEDGMENTS......Page 17
Contents......Page 6
Preface for the Fourth Edition......Page 14
Preface to the First Edition......Page 19
About the Authors......Page 25
1 INTRODUCTION......Page 26
  1.1 What Is Computer Science About?......Page 28
  1.2 Programming Languages......Page 31
  1.3 What Computers Understand......Page 34
  1.4 Media Computation: Why Digitize Media?......Page 36
   1.5.2 It’s About Process......Page 38
   1.5.3 You Will Probably Need It......Page 39
  2.1 Programming Is About Naming......Page 43
   2.1.1 Files and Their Names......Page 45
  2.2 Programming in Python......Page 46
  2.3 Programming in JES......Page 47
  2.4 Media Computation in JES......Page 48
   2.4.1 Showing a Picture......Page 52
   2.4.3 Naming Values......Page 55
  2.5 Making a Program......Page 58
   2.5.1 Functions: Real Math-Like Functions That Take Input......Page 62
  3.1 Strings: Making Human Text in a Computer......Page 69
   3.1.1 Making Strings from Strings: Telling Stories......Page 71
  3.2 Taking Strings Apart with For......Page 74
   3.2.1 Testing the Pieces......Page 76
   3.2.2 Taking String Apart, and Putting Strings Together......Page 79
   3.2.3 Taking Strings Apart with Indices......Page 82
   3.2.4 Mirroring, Reversing, and Separating Strings with Index......Page 84
   3.2.5 Encoding and Decoding Strings Using a Keyword Cipher......Page 86
  3.3 Taking Strings Apart by Words......Page 88
  3.4 What’s Inside a String......Page 91
  3.5 What a Computer Can Do......Page 92
 4 Modifying Pictures Using Loops......Page 99
  4.1 How Pictures Are Encoded......Page 100
  4.2 Manipulating Pictures......Page 105
   4.2.1 Exploring Pictures......Page 109
   4.3.1 Using Loops in Pictures......Page 111
   4.3.2 Increasing/Decreasing Red (Green, Blue)......Page 113
   4.3.3 Testing the Program: Did That Really Work?......Page 118
   4.3.4 Changing One Color at a Time......Page 119
   4.4.1 Making Sense of Functions......Page 120
  4.5 Lightening and Darkening......Page 125
  4.6 Creating a Negative......Page 126
  4.7 Converting to Grayscale......Page 127
  4.8 Specifying Pixels by Index......Page 129
  5.1 Replacing Colors: Red-Eye, Sepia Tones, and Posterizing......Page 139
   5.1.1 Reducing Red-Eye......Page 143
   5.1.2 Sepia-Toned and Posterized Pictures: Using Conditionals to Choose the Color......Page 145
  5.2 Comparing Pixels: Edge Detection......Page 151
  5.3 Background Subtraction......Page 154
  5.4 Chromakey......Page 157
   5.5.1 Adding a Border......Page 162
   5.5.2 Lightening the Right Half of a Picture......Page 163
  5.6 Selecting without Retesting......Page 164
  6.1 Processing Pixels Faster......Page 170
   6.1.1 Looping across the Pixels with Range......Page 172
   6.1.2 Writing Faster Pixel Loops......Page 174
  6.2 Mirroring a Picture......Page 176
  6.3 Copying and Transforming Pictures......Page 183
   6.3.1 Copying......Page 184
   6.3.2 Copying Smaller and Modifying......Page 190
   6.3.3 Copying and Referencing......Page 192
   6.3.4 Creating a Collage......Page 194
   6.3.5 General Copying......Page 197
   6.3.6 Rotation......Page 198
   6.3.7 Scaling......Page 201
  6.4 Combining Pixels: Blurring......Page 206
  6.5 Blending Pictures......Page 209
  6.6 Drawing on Images......Page 211
   6.6.1 Drawing with Drawing Commands......Page 213
   6.6.2 Vector and Bitmap Representations......Page 214
  6.7 Programs as Specifying Drawing Process......Page 216
   6.7.1 Why Do We Write Programs?......Page 217
2 SOUND......Page 226
   7.1.1 The Physics of Sound......Page 228
   7.1.2 Investigating Different Sounds......Page 231
   7.1.3 Encoding the Sound......Page 236
   7.1.4 Binary Numbers and Two’s Complement......Page 237
   7.1.5 Storing Digitized Sounds......Page 238
   7.2.1 Open Sounds and Manipulating Samples......Page 240
   7.2.2 Using the JES Media Tools......Page 243
   7.2.3 Looping......Page 244
   7.3.1 Increasing Volume......Page 245
   7.3.2 Did That Really Work?......Page 246
   7.3.3 Decreasing Volume......Page 250
   7.3.4 Using Array Index Notation......Page 251
  7.4 Normalizing Sounds......Page 252
   7.4.1 Generating Clipping......Page 254
  8.1 Manipulating Different Sections of the Sound Differently......Page 260
   8.1.1 Revisiting Index Array Notation......Page 261
  8.2 Splicing Sounds......Page 263
  8.3 General Clip and Copy......Page 270
  8.4 Reversing Sounds......Page 272
  8.6 On Functions and Scope......Page 274
  9.1 Composing Sounds Through Addition......Page 280
  9.2 Blending Sounds......Page 281
  9.3 Creating an Echo......Page 283
   9.3.2 Creating Chords......Page 285
  9.4 How Sampling Keyboards Work......Page 286
   9.5.1 Making Sine Waves......Page 290
   9.5.2 Adding Sine Waves Together......Page 292
   9.5.3 Checking Our Result......Page 293
   9.5.4 Square Waves......Page 294
   9.5.5 Triangular Waves......Page 296
   9.6.1 MP3......Page 298
   9.6.2 MIDI......Page 299
 10 Building Bigger Programs......Page 303
  10.1 Designing Programs Top-Down......Page 304
   10.1.1 A Top-Down Design Example......Page 305
   10.1.2 Designing the Top-Level Function......Page 306
   10.1.3 Writing the Subfunctions......Page 308
  10.2 Designing Programs Bottom-Up......Page 312
  10.3 Testing Your Program......Page 313
   10.3.1 Testing the Edge Conditions......Page 315
  10.4 Tips on Debugging......Page 316
   10.4.2 Seeing the Variables......Page 317
   10.4.3 Debugging the Adventure Game......Page 319
  10.5 Algorithms and Design......Page 322
  10.6 Connecting to Data Outside a Function......Page 323
  10.7 Running Programs Outside of JES......Page 327
3 TEXT, FILES, NETWORKS, DATABASES, AND UNIMEDIA......Page 334
  11.1 Text as Unimedia......Page 336
  11.2 Manipulating Parts of Strings......Page 337
   11.2.1 String Methods: Introducing Objects and Dot Notation......Page 338
   11.2.2 Lists: Powerful, Structured Text......Page 340
  11.3 Files: Places to Put Your Strings and Other Stuff......Page 342
   11.3.1 Opening and Manipulating Files......Page 344
   11.3.2 Generating Form Letters......Page 345
   11.3.3 Reading and Manipulating Data from the Internet......Page 346
   11.3.4 Scraping Information from a Web Page......Page 349
   11.3.5 Reading CSV Data......Page 350
   11.3.6 Writing Out Programs......Page 352
  11.4 The Python Standard Library......Page 353
   11.4.1 More on Import and Your Own Modules......Page 354
   11.4.2 Adding Unpredictably to Your Program with Random......Page 355
   11.4.4 A Sampling of Python Standard Libraries......Page 357
  12.1 Networks: Getting Our Text from the Web......Page 362
   12.1.1 Automating Access to CSV Data......Page 366
   12.1.2 Accessing FTP......Page 368
  12.2 Using Text to Shift Between Media......Page 369
  12.3 Moving Information Between Media......Page 372
  12.4 Using Lists as Structured Text for Media Representations......Page 375
  12.5 Hiding Information ina Picture......Page 376
   12.5.1 Hiding a Sound Inside a Picture......Page 378
  13.1 HTML: The Notation of the Web......Page 384
  13.2 Writing Programs to Generate HTML......Page 389
   13.2.1 Making Home Pages......Page 391
  13.3 Databases: A Place to Store Our Text......Page 394
   13.3.1 Relational Databases......Page 396
   13.3.2 An Example Relational Database Using Hash Tables......Page 397
   13.3.3 Working with SQL......Page 400
   13.3.4 Using a Database to Build Web Pages......Page 402
4 MOVIES......Page 408
 14 Creating and Modifying Movies......Page 410
  14.1 Generating Animations......Page 411
   14.2.1 Video Manipulating Examples......Page 420
  14.3 Building a Video Effect Bottom-Up......Page 424
  15.2 What Makes Programs Fast?......Page 431
   15.2.1 What Computers Really Understand......Page 432
   15.2.2 Compilers and Interpreters......Page 433
   15.2.3 What Limits Computer Speed?......Page 437
   15.2.4 Does It Really Make a Difference?......Page 439
   15.2.5 Making Searching Faster......Page 442
   15.2.6 Algorithms That Never Finish or Can’t Be Written......Page 444
  15.3 What Makes a Computer Fast?......Page 445
   15.3.1 Clock Rates and Actual Computation......Page 446
   15.3.2 Storage: What Makes a Computer Slow?......Page 447
   15.3.3 Display......Page 448
  16.1 Using Functions to Make Programming Easier......Page 451
  16.2 Functional Programming with Map and Reduce......Page 455
  16.3 Functional Programming for Media......Page 458
   16.3.1 Media Manipulation without Changing State......Page 459
  16.4 Recursion: A Powerful Idea......Page 460
   16.4.1 Recursive Directory Traversals......Page 465
   16.4.2 Recursive Media Functions......Page 467
  17.1 History of Objects......Page 472
   17.2.1 Classes and Objects......Page 474
   17.2.2 Sending Messages to Objects......Page 475
   17.2.3 Objects Control Their State......Page 477
  17.3 Teaching Turtles New Tricks......Page 479
   17.3.1 Overriding an Existing Turtle Method......Page 481
   17.3.2 Working with Multiple Turtles at Once......Page 482
   17.3.3 Turtles with Pictures......Page 484
   17.3.4 Dancing Turtles......Page 485
   17.3.5 Recursion and Turtles......Page 488
  17.4 An Object-Oriented Slide Show......Page 489
   17.4.1 Making the Slide Class More Object-Oriented......Page 492
  17.5 Object-Oriented Media......Page 494
  17.6 Joe the Box......Page 499
  17.7 Why Objects?......Page 500
  A.1 Variables......Page 507
  A.3 Loops and Conditionals......Page 508
  A.4 Operators andRepresentation Functions......Page 509
  A.8 Useful String Methods......Page 510
  A.12 External Modules......Page 511
  A.14 Functional Methods......Page 512
Bibliography......Page 513
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