TEAM LinG - Live, Informative, Non-cost and Genuine! Making Use of Python TEAM LinG - Live, Informative, Non-cost and Genuine! TEAM LinG - Live, Informative, Non-cost and Genuine! Making Use of Python Rashi Gupta Wiley Publishing, Inc. TEAM LinG - Live, Informative, Non-cost and Genuine! Publisher: Robert Ipsen Editor: Ben Ryan Managing Editor: Angela Smith New Media Editor: Brian Snapp Text Design & Composition: John Wiley Composition Services Designations used by companies to distinguish their products are often claimed as trade- marks. In all instances where John Wiley & Sons, Inc., is aware of a claim, the product names appear in initial capital or ALLCAPITALLETTERS. Readers, however, should contact the appro- priate companies for more complete information regarding trademarks and registration. This book is printed on acid-free paper. ∞ Copyright © 2002 by Rashi Gupta. All rights reserved. Published by Wiley Publishing, Inc., New York. Published simultaneously in Canada. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copy- right Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA01923, (978) 750-8400, fax (978) 750-4744. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 605 Third Avenue, New York, NY 10158-0012, (212) 850-6011, fax (212) 850-6008, E-Mail: PERMREQ @ WILEY.COM. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold with the understanding that the publisher is not engaged in professional services. If professional advice or other expert assistance is required, the services of a competent professional person should be sought. Library of Congress Cataloging-in-Publication Data: ISBN: 0471-21975-4 Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. Printed in the United States of America. 10 9 8 7 6 5 4 3 2 1 TEAM LinG - Live, Informative, Non-cost and Genuine! Contents Introduction xi Scenario xxiii Chapter 1 An Introduction to Python 1 Getting Started 1 Understanding Requirements 2 Determine Requirements of the University 2 Obtain Python and Its Documentation 3 Determine the System Requirements 4 Install Python 5 Start Python in Different Execution Modes 7 Summary 12 Chapter 2 Getting Started with Python 13 Getting Started 14 Writing Your First Python Program 14 Comments 15 Python as a Calculator 16 Using Variables in Python 16 Variables 17 Assigning Values to Variables 18 Standard Types 19 Identifiers and Keywords 39 Memory Management 40 Create a Sequence to Store All the Names of the Students 42 Write the Code to Display the Names of the Students 42 v TEAM LinG - Live, Informative, Non-cost and Genuine! vi Contents Declare a Dictionary of Student Purchases with the Names of the Students as the Key 43 Write the Code to Display the Student Purchases 43 Save and Execute the Code 43 Verify the Details 44 Summary 44 Chapter 3 Intrinsic Operations and Input/Output 47 Getting Started 48 Using Input/Output Features and Intrinsic Operations for Data Types in Python 48 Identify the Variables to Be Used 49 Accepting User Input 49 Formatting the Output 50 Introduction to Intrinsic Operations 55 Intrinsic Operations for Numeric Data Types 57 Intrinsic Operations for Strings 60 Intrinsic Operations for Lists and Tuples 66 Write the Code 71 Execute the Code 71 Summary 73 Chapter 4 Programming Basics 75 Getting Started 76 Conditional Operators 76 Order of Precedence of Operators 82 Using Programming Constructs 83 Identify the Control and Loop Statements to Be Used 84 Write the Code 94 Execute the Code 95 Summary 97 Chapter 5 Functions 99 Getting Started 100 Using Functions 100 Functions 101 Scope of Variables 118 Identify the Functions to Be Used 119 Write the Code 119 Execute the Code 121 Summary 122 Chapter 6 Modules 123 Getting Started 124 Using Modules 124 Modules 124 Packages 135 Identify the Modules to Be Used 136 TEAM LinG - Live, Informative, Non-cost and Genuine! Contents vii Write the Code 137 Execute the Code 139 Summary 140 Chapter 7 Files 141 Getting Started 141 Using File Objects 142 Identify the Functions and Methods to Be Used 142 Write the Code to Store Course Details to the File 154 Execute the Code 155 Verify the Solution 155 Summary 156 Chapter 8 Object-Oriented Programming 157 Getting Started 158 Introducing OOP 158 Components of OOP 159 Benefits of OOP 160 Using Classes 161 Identify the Classes to Be Defined 162 Identifying the Class Objects 163 Identifying the Classes to Be Inherited and Their Objects 170 Identify the Methods to Be Overridden 173 Write the Code 182 Execute the Code 189 Summary 190 Chapter 9 Exception Handling 193 Getting Started 193 Handling Exceptions 194 Identify the Type of Error and Where the Error Occurs 196 Identify the Mechanism of Trapping the Exception 200 Identify the Location for the Code for Handling the Exception to Be Written 209 Write the Code for Handling the Exception 209 Save and Execute the Code 210 Summary 210 Chapter 10 CGI Programming 213 Getting Started 213 Internet Basics 214 World Wide Web 217 Web Browsers 217 Hypertext Transfer Protocol (HTTP) 220 Revising HTML 221 Client-Side versus Server-Side Scripting 227 An Introduction to CGI 229 TEAM LinG - Live, Informative, Non-cost and Genuine! viii Contents Writing CGI Applications 231 Write the Code for the HTMLForm to Accept Data from the User 231 Write the CGI Program in Python to Generate the Results Page 232 Write the CGI Program to Generate Both the Form and Results Pages 236 Execute the Code 237 Summary 239 Chapter 11 Database Programming 241 Getting Started 241 Database Management 242 Introduction to MySQL 243 Working with MySQL 246 Accessing a Database from a Python Script 254 Identify the Elements of the Table That Stores Registration Details 256 Identify the Steps for Connecting to the Database 256 Write the Code to Create a Table in the Database 259 Write the Code to Insert the Registration Details into the Table Created 260 Execute the Code to Create the Table in the Database 261 Execute the Code to Insert Data into the Table 261 Verify the Data in the Database 263 Summary 264 Chapter 12 Network Programming 267 Getting Started 267 Client/Server Architecture 268 Network Programming 269 Using Sockets 272 Identify the Sockets to Be Used 272 Write the Code to Run on the IT Department Computer 287 Write the Code to Run on the Admission Office Computer 288 Execute the Code Created for the IT Department Computer 289 Execute the Code Created for the Admission Office Computer 290 Verify that Data Has Been Saved to a File in the IT Department Computer 292 Summary 292 Chapter 13 Multithreaded Programming 297 Getting Started 297 Single-Threaded Applications 298 Threading in Python 299 TEAM LinG - Live, Informative, Non-cost and Genuine! Contents ix Creating Multithreaded Applications 300 Identify the Class and the Methods to Create a Multithreaded Application 300 Write Code for the Server 308 Write the Code for the Client 309 Execute the Code Created for the Server 310 Execute the Code Created for the Client 311 Summary 313 Chapter14 Advanced Web Programming 315 Getting Started 316 Creating Web Servers 316 Accessing URLs 323 Creating Advanced CGI Applications 328 Identify the Elements of the Web Page for Entering Assignment Details and Uploading the File 328 Identify the Methodology for Uploading the File 329 Identify the Methodology for Storing User Information 330 Write the Code for the CGI Script 335 Execute the CGI Script 339 Summary 340 Chapter 15 GUI Programming with Tkinter 343 Getting Started 343 Introduction to Tkinter 344 Creating a GUI Application 347 Identify the Components of the User Interface 348 Identify the Tkinter Widgets to Design the User Interface 348 Write the Code for the User Interface 360 Execute the Code 362 Summary 364 Appendix A Distributing COM Objects 365 Basics of COM 365 The Binary Standard 367 COM Interfaces 369 Binding 370 Python and COM 371 Creating COM Clients 371 Creating COM Servers 373 Index 377 TEAM LinG - Live, Informative, Non-cost and Genuine!