Book Image

Python 3 Object Oriented Programming

By : Dusty Phillips
Book Image

Python 3 Object Oriented Programming

By: Dusty Phillips

Overview of this book

Object Oriented Programming is a very important aspect of modern programming languages. The basic principles of Object Oriented Programming are relatively easy to learn. Putting them together into working designs can be challenging.This book makes programming more of a pleasure than a chore using powerful Python 3 object-oriented features of Python 3. It clearly demonstrates the core OOP principles and how to correctly implement OOP in Python. Object Oriented Programming ranks high in importance among the many models Python supports. Yet, many programmers never bother learning the powerful features that make this language object oriented.The book teaches when and how OOP should be correctly applied. It emphasizes not only the simple syntax of OOP in Python, but also how to combine these objects into well-designed software.This book will introduce you to the terminology of the object-oriented paradigm, focusing on object-oriented design with step-by-step examples. It will take you from simple inheritance, one of the most useful tools in the object-oriented programmer's toolbox, all the way through to cooperative inheritance, one of the most complicated. You will be able to raise, handle, define, and manipulate exceptions.You will be able to integrate the object-oriented and the not-so-object-oriented aspects of Python. You will also be able to create maintainable applications by studying higher level design patterns. You'll learn the complexities of string and file manipulation, and how Python distinguishes between binary and textual data. Not one, but two very powerful automated testing systems will be introduced to you. You'll understand the joy of unit testing and just how easy they are to create. You'll even study higher level libraries such as database connectors and GUI toolkits and how they apply object-oriented principles.
Table of Contents (18 chapters)
Python 3 Object Oriented Programming
Credits
About the Author
About the Reviewers
Preface
Index

Singleton pattern


The singleton pattern is one of the most controversial patterns; many have accused it of being an "anti-pattern"; a pattern that should be avoided, not promoted. In Python, if someone is using the singleton pattern, they're almost certainly doing something wrong, probably because they're coming from a more restrictive programming language.

So why discuss it at all? Singleton is one of the most famous of all design patterns. It is very useful in overly object-oriented languages, and is a vital part of object-oriented programming. Finally, the idea behind singleton is useful, even if we implement that idea in a totally different way in Python.

The basic idea behind the singleton pattern is to allow exactly one instance of a certain object to exist. Typically, this object is a sort of manager class like those we discussed in Chapter 5. Such objects often need to be referenced by a wide variety of other objects, and passing references to the manager object around to the methods...