Book Image

Python Object-Oriented Programming - Fourth Edition

By : Steven F. Lott, Dusty Phillips
2 (2)
Book Image

Python Object-Oriented Programming - Fourth Edition

2 (2)
By: Steven F. Lott, Dusty Phillips

Overview of this book

Object-oriented programming (OOP) is a popular design paradigm in which data and behaviors are encapsulated in such a way that they can be manipulated together. Python Object-Oriented Programming, Fourth Edition dives deep into the various aspects of OOP, Python as an OOP language, common and advanced design patterns, and hands-on data manipulation and testing of more complex OOP systems. These concepts are consolidated by open-ended exercises, as well as a real-world case study at the end of every chapter, newly written for this edition. All example code is now compatible with Python 3.9+ syntax and has been updated with type hints for ease of learning. Steven and Dusty provide a comprehensive, illustrative tour of important OOP concepts, such as inheritance, composition, and polymorphism, and explain how they work together with Python’s classes and data structures to facilitate good design. In addition, the book also features an in-depth look at Python’s exception handling and how functional programming intersects with OOP. Two very powerful automated testing systems, unittest and pytest, are introduced. The final chapter provides a detailed discussion of Python's concurrent programming ecosystem. By the end of the book, you will have a thorough understanding of how to think about and apply object-oriented principles using Python syntax and be able to confidently create robust and reliable programs.
Table of Contents (17 chapters)
15
Other Books You May Enjoy
16
Index

Abstract Base Classes and Operator Overloading

We often need to make a distinction between concrete classes that have a complete set of attributes and methods, and an abstract class that is missing some details. This parallels the philosophical idea of abstraction as a way to summarize complexities. We might say that a sailboat and an airplane have a common, abstract relationship of being vehicles, but the details of how they move are distinct.

In Python, we have two approaches to defining similar things:

  • Duck typing: When two class definitions have the same attributes and methods, then instances of the two classes have the same protocol and can be used interchangeably. We often say, "When I see a bird that walks like a duck and swims like a duck and quacks like a duck, I call that bird a duck."
  • Inheritance: When two class definitions have common aspects, a subclass can share common features of a superclass. The...