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

Iterators

In typical design pattern parlance, an iterator is an object with a next() method and a done() method; the latter returns True if there are no items left in the sequence. In a programming language without built-in support for iterators, the iterator would be used like this:

while not iterator.done(): 
    item = iterator.next() 
    # do something with the item 

In Python, iteration is available across many language features, so the method gets a special name, __next__. This method can be accessed using the next(iterator) built-in. Rather than a done() method, Python's iterator protocol raises the StopIteration exception to notify the client that the iterator has completed. Finally, we have the much more readable for item in iterator: syntax to actually access items in an iterator instead of messing around with a while statement. Let's look at each these in more detail.

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