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
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16
Index

Case study

In this chapter, we'll continue developing elements of the case study. We want to explore some additional features of object-oriented design in Python. The first is what is sometimes called "syntactic sugar," a handy way to write something that offers a simpler way to express something fairly complex. The second is the concept of a manager for providing a context for resource management.

In Chapter 4, Expecting the Unexpected, we built an exception for identifying invalid input data. We used the exception for reporting when the inputs couldn't be used.

Here, we'll start with a class to gather data by reading the file with properly classified training and test data. In this chapter, we'll ignore some of the exception-handling details so we can focus on another aspect of the problem: partitioning samples into testing and training subsets.

Input validation

The TrainingData object is loaded from a source file of samples...