Introduction to Python Programming

465 Pages·2019·14.11 MB·English

by  Gowrishankar S.

Introduction to
Python Programming

Introduction to
Python  Programming
Gowrishankar S.
Veena A.
CRC Press
Taylor & Francis Group
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Library of Congress Cataloging‑in‑Publication Data
Names: S, Gowrishankar, author. | A, Veena author.
Title: Introduction to Python programming / Gowrishankar S, Veena A.
Description: Boca Raton : Taylor & Francis, a CRC title, part of the Taylor &
Francis imprint, a member of the Taylor & Francis Group, the academic
division of T&F Informa, plc, 2018. | Includes bibliographical references
and index.
Identifiers: LCCN 2018046894 | ISBN 9780815394372 (hardback : alk. paper) |
ISBN 9781351013239 (ebook)
Subjects: LCSH: Python (Computer program language)
Classification: LCC QA76.73.P98 S2325 2018 | DDC 005.13/3--dc23
LC record available at https://lccn.loc.gov/2018046894
Visit the Taylor & Francis Web site at
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Dedicated to my wife Roopa K. M. and to my sister Ashwini S. Nath.
—Dr. Gowrishankar S.
I would love to dedicate this book to my parents, and my family
for their love, support and encouragement.
—Veena A.

Contents
Preface ...........................................................................................................................................xiii
Acknowledgment .......................................................................................................................xvii
Authors .........................................................................................................................................xix
1. Introduction .............................................................................................................................1
1.1 What Is a Program? ....................................................................................................1
1.2 Programming Languages ..........................................................................................2
1.2.1 Machine Language ......................................................................................2
1.2.2 Assembly Language ....................................................................................3
1.2.3 High-Level Language .................................................................................3
1.3 Software Development ...............................................................................................5
1.4 History of Python Programming Language ...........................................................7
1.5 Thrust Areas of Python..............................................................................................8
1.5.1 Academia ......................................................................................................9
1.5.2 Scientific Tools ...........................................................................................10
1.5.3 Machine Learning .....................................................................................10
1.5.4 Natural Language Processing .................................................................10
1.5.5 Data Analysis .............................................................................................10
1.5.6 Statistics ......................................................................................................11
1.5.7 Hypertext Transfer Protocol (HTTP) Library ........................................11
1.5.8 Database Connectors/ORM/NoSQL Connectors ................................11
1.5.9 Web Frameworks .......................................................................................11
1.5.10 Cloud Computing......................................................................................11
1.5.11 Python Distributions ................................................................................12
1.5.12 IDE Available .............................................................................................12
1.5.13 Community ................................................................................................12
1.5.14 Python Stack in Industry .........................................................................12
1.6 Installing Anaconda Python Distribution ............................................................13
1.7 Installing PyCharm IDE to Set Up a Python Development Environment .......16
1.8 Creating and Running Your First Python Project ................................................19
1.9 Installing and Using Jupyter Notebook.................................................................23
1.9.1 Starting Jupyter Notebook .......................................................................24
1.10 Open Source Software .............................................................................................27
1.10.1 Why Do People Prefer Using Open Source Software? ........................28
1.10.2 Doesn’t “Open Source” Just Mean Something Is Free of Charge? .....29
1.10.3 Open Source Licenses ...............................................................................29
1.11 Summary ....................................................................................................................32
Multiple Choice Questions ...................................................................................................32
Review Questions ..................................................................................................................34
2. Parts of Python Programming Language ........................................................................35
2.1 Identifiers ...................................................................................................................35
2.2 Keywords ...................................................................................................................36
vii
viii Contents
2.3 Statements and Expressions ....................................................................................36
2.4 Variables .....................................................................................................................37
2.4.1 Legal Variable Names ...............................................................................37
2.4.2 Assigning Values to Variables .................................................................37
2.5 Operators ....................................................................................................................38
2.5.1 Arithmetic Operators ................................................................................39
2.5.2 Assignment Operators ..............................................................................40
2.5.3 Comparison Operators .............................................................................42
2.5.4 Logical Operators ......................................................................................43
2.5.5 Bitwise Operators ......................................................................................44
2.6 Precedence and Associativity .................................................................................47
2.7 Data Types ..................................................................................................................48
2.7.1 Numbers .....................................................................................................48
2.7.2 Boolean .......................................................................................................48
2.7.3 Strings .........................................................................................................48
2.7.4 None ............................................................................................................49
2.8 Indentation .................................................................................................................49
2.9 Comments ..................................................................................................................50
2.9.1 Single Line Comment ...............................................................................50
2.9.2 Multiline Comments .................................................................................50
2.10 Reading Input ............................................................................................................50
2.11 Print Output ...............................................................................................................51
2.11.1 str.format() Method ....................................................................................51
2.11.2 f-strings .......................................................................................................53
2.12 Type Conversions ......................................................................................................54
2.12.1 The int() Function ......................................................................................54
2.12.2 The float() Function....................................................................................55
2.12.3 The str() Function ......................................................................................55
2.12.4 The chr() Function .....................................................................................56
2.12.5 The complex() Function .............................................................................56
2.12.6 The ord() Function .....................................................................................57
2.12.7 The hex() Function .....................................................................................57
2.12.8 The oct() Function ......................................................................................57
2.13 The type() Function and Is Operator ......................................................................58
2.14 Dynamic and Strongly Typed Language ..............................................................58
2.15 Summary ....................................................................................................................59
Multiple Choice Questions ...................................................................................................60
Review Questions ..................................................................................................................65
3. Control Flow Statements .....................................................................................................67
3.1 The if Decision Control Flow Statement ................................................................68
3.2 The if…else Decision Control Flow Statement .......................................................69
3.3 The if…elif…else Decision Control Statement ........................................................71
3.4 Nested if Statement ...................................................................................................73
3.5 The while Loop ...........................................................................................................74
3.6 The for Loop ...............................................................................................................79
3.7 The continue and break Statements ..........................................................................81
Contents ix
3.8 Catching Exceptions Using try and except Statement ..........................................84
3.8.1 Syntax Errors ..............................................................................................84
3.8.2 Exceptions ..................................................................................................84
3.8.3 Exception Handling Using try…except…finally .....................................85
3.9 Summary ....................................................................................................................89
Multiple Choice Questions ...................................................................................................90
Review Questions ..................................................................................................................93
4. Functions ................................................................................................................................95
4.1 Built-In Functions .....................................................................................................95
4.2 Commonly Used Modules .......................................................................................97
4.3 Function Definition and Calling the Function .....................................................99
4.4 The return Statement and void Function ..............................................................103
4.5 Scope and Lifetime of Variables ...........................................................................106
4.6 Default Parameters .................................................................................................108
4.7 Keyword Arguments ..............................................................................................109
4.8 *args and **kwargs ..................................................................................................110
4.9 Command Line Arguments ..................................................................................112
4.10 Summary ..................................................................................................................113
Multiple Choice Questions .................................................................................................113
Review Questions ................................................................................................................117
5. Strings ...................................................................................................................................119
5.1 Creating and Storing Strings .................................................................................119
5.1.1 The str() Function ....................................................................................120
5.2 Basic String Operations ..........................................................................................120
5.2.1 String Comparison ..................................................................................122
5.2.2 Built-In Functions Used on Strings ......................................................122
5.3 Accessing Characters in String by Index Number .............................................123
5.4 String Slicing and Joining ......................................................................................124
5.4.1 Specifying Steps in Slice Operation ......................................................126
5.4.2 Joining Strings Using join() Method .....................................................127
5.4.3 Split Strings Using split() Method .........................................................127
5.4.4 Strings Are Immutable ...........................................................................128
5.4.5 String Traversing .....................................................................................128
5.5 String Methods ........................................................................................................131
5.6 Formatting Strings ..................................................................................................138
5.6.1 Format Specifiers .....................................................................................140
5.6.2 Escape Sequences ....................................................................................141
5.6.3 Raw Strings ..............................................................................................142
5.6.4 Unicodes ...................................................................................................142
5.7 Summary ..................................................................................................................143
Multiple Choice Questions .................................................................................................143
Review Questions ................................................................................................................146
6. Lists........................................................................................................................................149
6.1 Creating Lists ...........................................................................................................149
6.2 Basic List Operations ..............................................................................................151
6.2.1 The list() Function ....................................................................................151