Python 3 Object-oriented Programming - Second Edition

Dusty Phillips

• Verlag: Packt Publishing
• Jahr: 2015
• ISBN:
  9781784395957
• Auflage: 2
• Thema: Computer Science
• Thema: Object Oriented Programming

About This Book

• Stop writing scripts and start architecting programs
• Learn the latest Python syntax and libraries
• A practical, hands-on tutorial that teaches you all about abstract design patterns and how to implement them in Python 3

Who This Book Is For

If you're new to object-oriented programming techniques, or if you have basic Python skills and wish to learn in depth when to correctly apply object-oriented programming in Python to design software, this is the book for you.

What You Will Learn

• Implement objects in Python by creating classes and defining methods
• Separate related objects into a taxonomy of classes and describe the properties and behaviors of those objects via the class interface
• Extend class functionality by using inheritance
• Understand when to use object-oriented features, and more importantly, when not to use them
• Discover what design patterns are and why they are different in Python
• Uncover the simplicity of unit testing and why it's so important in Python
• Grasp common concurrency techniques and pitfalls in Python 3
• Explore the new AsyncIO module for developing massively concurrent network systems

In Detail

Python 3 Object-oriented Programming, Second Edition, explains classes, data encapsulation, inheritance, polymorphism, abstraction, and exceptions with an emphasis on when you can use each principle to develop well-designed software. It will not only guide you to create maintainable applications by studying higher level design patterns but will also help you grasp the complexities of string and file manipulation, and how Python distinguishes between binary and textual data. As a bonus, you will also discover the joys of unit testing and the complexities of concurrent programming.

This book is packed with updated content to reflect recent changes to the core Python library that were not available when the highly rated first edition was originally published. It has also been restructured and reorganized to improve the flow of knowledge and enhance the reading experience.

Python 3 Object-oriented Programming Second Edition

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Table of Contents

Python 3 Object-oriented Programming Second Edition

Credits

About the Author

About the Reviewers

www.PacktPub.com

Support files, eBooks, discount offers, and more

Why subscribe?

Free access for Packt account holders

Introduction to the second edition

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Errata

Piracy

Questions

1. Object-oriented Design

Introducing object-oriented

Objects and classes

Specifying attributes and behaviors

Data describes objects

Behaviors are actions

Hiding details and creating the public interface

Composition

Inheritance

Inheritance provides abstraction

Multiple inheritance

Case study

Exercises

Summary

2. Objects in Python

Creating Python classes

Adding attributes

Making it do something

Talking to yourself

More arguments

Initializing the object

Explaining yourself

Modules and packages

Organizing the modules

Absolute imports

Relative imports

Organizing module contents

Who can access my data?

Third-party libraries

Case study

Exercises

Summary

3. When Objects Are Alike

Basic inheritance

Extending built-ins

Overriding and super

Multiple inheritance

The diamond problem

Different sets of arguments

Polymorphism

Abstract base classes

Using an abstract base class

Creating an abstract base class

Demystifying the magic

Case study

Exercises

Summary

4. Expecting the Unexpected

Raising exceptions

Raising an exception

The effects of an exception

Handling exceptions

The exception hierarchy

Defining our own exceptions

Case study

Exercises

Summary

5. When to Use Object-oriented Programming

Treat objects as objects

Adding behavior to class data with properties

Properties in detail

Decorators – another way to create properties

Deciding when to use properties

Manager objects

Removing duplicate code

In practice

Case study

Exercises

Summary

6. Python Data Structures

Empty objects

Tuples and named tuples

Named tuples

Dictionaries

Dictionary use cases

Using defaultdict

Counter

Lists

Sorting lists

Sets

Extending built-ins

Queues

FIFO queues

LIFO queues

Priority queues

Case study

Exercises

Summary

7. Python Object-oriented Shortcuts

Python built-in functions

The len() function

Reversed

Enumerate

File I/O

Placing it in context

An alternative to method overloading

Default arguments

Variable argument lists

Unpacking arguments

Functions are objects too

Using functions as attributes

Callable objects

Case study

Exercises

Summary

8. Strings and Serialization

Strings

String manipulation

String formatting

Escaping braces

Keyword arguments

Container lookups

Object lookups

Making it look right

Strings are Unicode

Converting bytes to text

Converting text to bytes

Mutable byte strings

Regular expressions

Matching patterns

Matching a selection of characters

Escaping characters

Matching multiple characters

Grouping patterns together

Getting information from regular expressions

Making repeated regular expressions efficient

Serializing objects

Customizing pickles

Serializing web objects

Case study

Exercises

Summary

9. The Iterator Pattern

Design patterns in brief

Iterators

The iterator protocol

Comprehensions

List comprehensions

Set and dictionary comprehensions

Generator expressions

Generators

Yield items from another iterable

Coroutines

Back to log parsing

Closing coroutines and throwing exceptions

The relationship between coroutines, generators, and functions

Case study

Exercises

Summary

10. Python Design Patterns I

The decorator pattern

A decorator example

Decorators in Python

The observer pattern

An observer example

The strategy pattern

A strategy example

Strategy in Python

The state pattern

A state example

State versus strategy

State transition as coroutines

The singleton pattern

Singleton implementation

The template pattern

A template example

Exercises

Summary

11. Python Design Patterns II

The adapter pattern

The facade pattern

The flyweight pattern

The command pattern

The abstract factory pattern

The composite pattern

Exercises

Summary

12. Testing Object-oriented Programs

Why test?

Test-driven development

Unit testing

Assertion methods

Reducing boilerplate and cleaning up

Organizing and running tests

Ignoring broken tests

Testing with py.test

One way to do setup and cleanup

A completely different way to set up variables

Skipping tests with py.test

Imitating expensive objects

How much testing is enough?

Case study

Implementing it

Exercises

Summary

13. Concurrency

Threads

The many problems with threads

Shared memory

The global interpreter lock

Thread overhead

Multiprocessing

Multiprocessing pools

Queues

The problems with multiprocessing

Futures

AsyncIO

AsyncIO in action

Reading an AsyncIO future

AsyncIO for networking

Using executors to wrap blocking code

Streams

Executors

Case study

Exercises

Summary

Index

Python 3 Object-oriented Programming Second Edition

Copyright © 2015 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: July 2010

Second edition: August 2015

Production reference: 1130815

Published by Packt Publishing Ltd.

Livery Place

35 Livery Street

Birmingham B3 2PB, UK.

ISBN 978-1-78439-878-1

www.packtpub.com

Credits

Author

Dusty Phillips

Reviewers

AMahdy AbdElAziz

Grigoriy Beziuk

Krishna Bharadwaj

Justin Cano

Anthony Petitbois

Claudio Rodriguez

Commissioning Editor

Edward Gordon

Acquisition Editors

Indrajit Das

Rebecca Pedley

Greg Wild

Content Development Editors

Divij Kotian

Arvind Koul

Anila Vincent

Technical Editor

Siddhi Rane

Copy Editor

Janbal Dharmaraj

Project Coordinator

Neha Bhatnagar

Proofreader

Safis Editing

Indexer

Hemangini Bari

Graphics

Sheetal Aute

Jason Monteiro

Production Coordinator

Komal Ramchandani

Cover Work

Komal Ramchandani

About the Author

Dusty Phillips is a Canadian software developer and author currently living in Seattle, Washington. He has been active in the open source community for a decade and a half and programming in Python for nearly all of it. He cofounded the popular Puget Sound Programming Python meetup group; drop by and say hi if you're in the area.

Python 3 Object Oriented Programming, Packt Publishing, was the first of his books. He has also written Creating Apps In Kivy, O'Reilly, the mobile Python library, and self-published Hacking Happy, a journey to mental wellness for the technically inclined. He was hospitalized for suicidal tendencies shortly after the first edition of this book was published and has been an outspoken proponent for positive mental health ever since.

About the Reviewers

AMahdy AbdElAziz has more than 8 years of experience in software engineering using several languages and frameworks. Over the last 5 years, he has focused on Android and mobile development, including cross-platform tools, and Android internals, such as building custom ROMs and customizing AOSP for embedded devices.

He is currently teaching Python at Information Technology Institution. You can visit his website, http://www.amahdy.net/, to find out more about him.

Grigoriy Beziuk is a former CIO of Crowdage Foundation, acting as an independent software developer as this book was being written. He has worked with a wide variety of programming languages and technologies, including different versions of Python in different environments, ranging from purely scientific ones to modern production-scale web development issues.

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