Charles Dierbach. Wiley

Transcription

1 Charles Dierbach Wiley

2 Contents Preface Acknowledgments About the Author XXI xxv xxvii Introduction 1 MOTIVATION 2 FUNDAMENTALS What Is Computer Science? The Essence of Computational Problem Solving Limits of Computational Problem Solving 5 Self-Test Questions Computer Algorithms What, Is an Algorithm? Algorithms and Computers: Self-Test Questions Computer Hardware 9 A Perfect Match Digital Computing: It's All about Switches The Binary Number System Fundamental Hardware Components Operating Systems Bridging Software and Hardware Limits of Integrated Circuits Technology: Moore's Law 12 Self-Test Questions Computer Software What Is Computer Software? Syntax, Semantics, and Program Translation Procedural vs. Object-Oriented Programming 17 Self-Test Questions 17 COMPUTATIONAL PROBLEM SOLVING The Process of Computational Problem Solving Problem Analysis Program Design Program Implementation Program Testing 21

3 x Contents 1.6 The Python Programming Language About Python The IDLE Python Development Environment The Python Standard Library A Bit of Python Learning How to Use IDLE A First Program Calculating the Drake Equation The Problem Problem Analysis Program Design Program Implementation Program Testing 32 Chapter Summary 33 Chapter Exercises 34 Python Programming Exercises 36 Program Modification Problems 37 Program Development Problems 37 Data and Expressions 38 MOTIVATION 39 FUNDAMENTAL CONCEPTS Literals What Is a Literal? Numeric Literals String Literals Control Characters String Formatting Implicit and Explicit Line Joining Let's Apply It "Hello World Unicode Encoding" 48 Self-Test Questions Variables and Identifiers What Is a Variable? Variable Assignment and Keyboard Input What Is an Identifier? Keywords and Other Predefined Identifiers in Python Let's Apply It "Restaurant Tab Calculation" 55 Self-Test Questions Operators What Is an Operator? Arithmetic Operators Let's Apply It "Your Place in the Universe" 59 Self-Test Questions Expressions and Data Types What Is an Expression? Operator Precedence Operator Associativity 63

4 Contents xi What Is a Data Type? Mixed-Type Expressions Let's Apply It "Temperature Conversion Program" 65 Self-Test Questions 66 COMPUTATIONAL PROBLEM SOLVING Age in Seconds Program The Problem Problem Analysis Program Design Program Implementation and Testing 69 Chapter Summary 74 Chapter Exercises 74 Python Programming Exercises 76 Program Modification Problems 76 Program Development Problems 77 Control Structures 79 MOTIVATION 80 FUNDAMENTAL CONCEPTS What Is a Control Structure? Boolean Expressions (Conditions) Relational Operators Membership Operators Boolean Operators Operator Precedence and Boolean Expressions Short-Circuit (Lazy) Evaluation Logically Equivalent Boolean Expressions 87 Self-Test Questions Selection Control If Statement Indentation in Python Multi-Way Selection Let's Apply It Number of Days in Month Program 94 Self-Test Questions Iterative Control While Statement Input Error Checking Infinite loops Definite vs. Indefinite Loops Boolean Flags and Indefinite Loops Let's Apply It Coin Change Exercise Program 101 Self-Test Questions 104 COMPUTATIONAL PROBLEM SOLVING Calendar Month Program The Problem 104

5 3.5.2 Problem Analysis Program Design Program Implementation and Testing 107 Chapter Summary 117 Chapter Exercises 118 Python Programming Exercises 120 Program Modification Problems 121 Program Development Problems 123 Lists 125 MOTIVATION 126 FUNDAMENTAL CONCEPTS List Structures What Is a List? Common List Operations List Traversal 128 Self-Test Questions Lists (Sequences) in Python Python List Type Tuples Sequences Nested Lists Let's Apply It A Chinese Zodiac Program 135 Self-Test Questions Iterating Over Lists (Sequences) in Python For Loops The Built-in range Function Iterating Over List Elements vs. List Index Values While Loops and Lists (Sequences) Let's Apply It Password Encryption/Decryption Program 141 Self-Test Questions More on Python Lists Assigning and Copying Lists List Comprehensions 146 COMPUTATIONAL PROBLEM SOLVING Calendar Year Program The Problem Problem Analysis Program Design Program Implementation and Testing 149 Chapter Summary 161 Chapter Exercises 162 Python Programming Exercises 164 Program Modification Problems 164 Program Development Problems 165

6 Contents xiii Functions 168 MOTIVATION 169 FUNDAMENTAL CONCEPTS Program Routines What Is a Function Routine? Defining Functions Let's Apply It Temperature Conversion Program (Function Version) 173 Self-Test Questions More on Functions Calling Value-Returning Functions Calling Non-Value-Returning Functions Parameter Passing Keyword Arguments in Python Default Arguments in Python Variable Scope Let's Apply It GPA Calculation Program 186 Self-Test Questions 189 COMPUTATIONAL PROBLEM SOLVING Credit Card Calculation Program The Problem Problem Analysis Program Design Program Implementation and Testing 191 Chapter Summary 202 Chapter Exercises 202 Python Programming Exercises 203 Program Modification Problems 204 Program Development Problems 204 Objects and Their Use 206 MOTIVATION 207 FUNDAMENTAL CONCEPTS Software Objects What Is an Object? Object References 209 Self-Test Questions Turtle Graphics Creating a Turtle Graphics The "Default" Turtle 218 Window Fundamental Turtle Attributes and Behavior Additional Turtle Attributes Creating Multiple Turtles 225

7 xiv Contents Let's Apply It Bouncing Balls Program 226 Self-Test Questions 229 COMPUTATIONAL PROBLEM SOLVING Horse Race Simulation Program The Problem Problem Analysis Program Design Program Implementation and Testing 231 Chapter Summary 243 Chapter Exercises 243 Python Programming Exercises 244 Program Modification Problems 245 Program Development Problems 246 j^j Modular Design 247 MOTIVATION 248 FUNDAMENTAL CONCEPTS Modules What Is a Module? Module Specification 249 Self-Test Questions Top-Down Design Developing a Modular Design of the Calendar Year Program Specification of the Calendar Year Program Self-Test Questions 255 Modules Python Modules What Is a Python Module? Modules and Namespaces Importing Modules Module Loading and Execution Local, Global, and Built-in Namespaces in Python A Programmer-Defined Stack Module Let's Apply It A Palindrome Checker Program 267 Self-Test Questions 268 COMPUTATIONAL PROBLEM SOLVING Calendar Year Program (function version) The Problem Problem Analysis Program Design Program Implementation and Testing 269 Chapter Summary 284 Chapter Exercises 284 Python Programming Exercises 286 Program Modification Problems 287 Program Development Problems 287

8 Text Files 289 MOTIVATION 290 FUNDAMENTAL CONCEPTS What Is a Text File? Using Text Files Opening Text Files Reading Text Files Writing Text Files 294 Self-Test Questions String Processing String Traversal String-Applicable Sequence Operations String Methods Let's Apply It Sparse Text Program 300 Self-Test Questions Exception Handling What Is an Exception? The Propagation of Raised Exceptions Catching and Handling Exceptions Exception Handling and User Input Exception Handling and File Processing Let's Apply It Word Frequency Count Program 310 Self-Test Questions 314 COMPUTATIONAL PROBLEM SOLVING Cigarette Use/Lung Cancer Correlation Program The Problem Problem Analysis Program Design Program Implementation and Testing Determining the Correlation Between Smoking and Lung Cancer 331 Chapter Summary 331 Chapter Exercises 332 Python Programming Exercises 333 Program Modification Problems 333 Program Development Problems 334 Dictionaries and Sets 337 MOTIVATION 338 FUNDAMENTAL CONCEPTS Dictionary Type in Python What Is a Dictionary? Let's Apply It Phone Number Spelling Program 342 Self-Test Questions 346

9 xvi Contents 9.2 Set Data Type The Set Data Type in Python Let's Apply It Kitchen Tile Visualization Program 348 Self-Test Questions 356 COMPUTATIONAL PROBLEM SOLVING A Food Co-op's Worker Scheduling The Problem Problem Analysis Program Design 358 Simulation Program Implementation and Testing Analyzing a Scheduled vs. Unscheduled Co-op Worker Approach 375 Chapter Summary 379 Chapter Exercises 379 Python Programming Exercises 380 Program Modification Problems 380 Program Development Problems 381 Object-Oriented Programming 383 MOTIVATION 384 FUNDAMENTAL CONCEPTS What Is Object-Oriented Programming? What Is a Class? Three Fundamental Features of Object-Oriented Programming Encapsulation What Is Encapsulation? Defining Classes in Python Let's Apply It A Recipe Conversion Program 394 Self-Test Questions Inheritance What Is Inheritance? Subtypes Defining Subclasses in Python Let's Apply It A Mixed Fraction Class 407 Self-Test Questions Polymorphism What Is Polymorphism? The Use of Polymorphism 414 Self-Test Questions Object-Oriented Design Using UML What Is UML? UML Class Diagrams 418 Self-Test Questions 422 COMPUTATIONAL PROBLEM SOLVING Vehicle Rental Agency Program The Problem 423

10 Contents xvii Problem Analysis Program Design Program Implementation and Testing 429 Chapter Summary 453 Chapter Exercises 454 Python Programming Exercises 455 Program Modification Problems 456 Program Development Problems 457 Recursion 460 MOTIVATION 461 FUNDAMENTAL CONCEPTS Recursive Functions What Is a Recursive Function? The Factorial Function Let's Apply It Fractals (Sierpinski Triangle) 467 Self-Test Questions Recursive Problem Solving Thinking Recursively MergeSort Recursive Algorithm Let's Apply It MergeSort Implementation 474 Self-Test Questions Iteration vs. Recursion 476 COMPUTATIONAL PROBLEM SOLVING Towers of Hanoi The Problem Problem Analysis Program Design and Implementation 481 Chapter Summary 487 Chapter Exercises 487 Python Programming Exercises 488 Program Modification Problems 489 Program Development Problems 490 Computing and Its Developments 491 CONTRIBUTIONS TO THE MODERN COMPUTER The Concept of a Programmable Computer "Father of the Modern Computer" Charles Babbage (1800s) "The First Computer Programmer" Ada Lovelace (1800s) Developments Leading to Electronic Computing The Development of Boolean Algebra (mid-1800s) The Development of the Vacuum Tube (1883) The Development of Digital Electronic Logic Gates (1903) 494

11 xviii Contents The Development of Memory Electronic Circuits (1919) The Development of Electronic Digital Logic Circuits (1937) "The Father of Information Theory" Claude Shannon (1948) 496 FIRST-GENERATION COMPUTERS (1940s-mid- 1950s) The Early Groundbreakers The Z3 The First Programmable Computer (1941) The Mark I First Computer Project in the United States ( ) The ABC The First Fully Electronic Computing Device (1942) Colossus A Special-Purpose Electronic Computer (1943) ENIAC The First Fully Electronic Programmable Computer EDVAC/ACE The First Stored Program Computers (1950) Whirlwind The First Real-Time Computer (1951) The First Commercially Available Computers The Struggles of the Eckert-Mauchly Computer Corporation (1950) The LEO Computer of the J. Lyons and Company (1951) 504 SECOND-GENERATION COMPUTERS (mid-1950s to mid-1960s) Transistorized Computers The Development of the Transistor (1947) The First Transistor Computer (1953) The Development of High-Level Programming Languages The Development of Assembly Language (early 1950s) The First High-Level Programming Languages (mid-1950s) The First "Program Bug" (1947) 508 THIRD-GENERATION COMPUTERS (mid-1960s to early 1970s) The Development of the Integrated Circuit (1958) The Catalyst for Integrated Circuit Advancements (1960s) The Development of the Microprocessor (1971) Mainframes, Minicomputers, and Supercomputers The Establishment of the Mainframe Computer (1962) The Development of the Minicomputer (1963) The Development of the UNDC Operating System (1969) The Development of Graphical User Interfaces (early 1960s) The Development of the Supercomputer (1972) 515 FOURTH-GENERATION COMPUTERS (early 1970s to the Present) The Rise of the Microprocessor The First Commercially Available Microprocessor (1971) The First Commercially Available Microcomputer Kit (1975) The Dawn of Personal Computing The Beginnings of Microsoft (1975) The Apple II (1977) IBM's Entry into the Microcomputer Market (1981) Society Embraces the Personal Computer (1983) The Development of Graphical User Interfaces (GUIs) The Development of the C+ + Programming Language 519

12 Contents xlx THE DEVELOPMENT OF COMPUTER NETWORKS The Development of Wide Area Networks Theldeaof Packet-Switched Networks (early 1960s) The First Packet-Switched Network: ARPANET (1969) The Development of Local Area Networks (LANs) The Need for Local Area Networks The Development of Ethernet (1980) The Development of the Internet and World Wide Web The Realization of the Need for "Internetworking" The Development of the TCP/IP Internetworking Protocol (1973) The Development of the World Wide Web (1990) The Development of the Java Programming Language (1995) 523 Appendix Index