Book Image

Mastering Python 2E - Second Edition

By : Rick van Hattem
5 (1)
Book Image

Mastering Python 2E - Second Edition

5 (1)
By: Rick van Hattem

Overview of this book

Even if you find writing Python code easy, writing code that is efficient, maintainable, and reusable is not so straightforward. Many of Python’s capabilities are underutilized even by more experienced programmers. Mastering Python, Second Edition, is an authoritative guide to understanding advanced Python programming so you can write the highest quality code. This new edition has been extensively revised and updated with exercises, four new chapters and updates up to Python 3.10. Revisit important basics, including Pythonic style and syntax and functional programming. Avoid common mistakes made by programmers of all experience levels. Make smart decisions about the best testing and debugging tools to use, optimize your code’s performance across multiple machines and Python versions, and deploy often-forgotten Python features to your advantage. Get fully up to speed with asyncio and stretch the language even further by accessing C functions with simple Python calls. Finally, turn your new-and-improved code into packages and share them with the wider Python community. If you are a Python programmer wanting to improve your code quality and readability, this Python book will make you confident in writing high-quality scripts and taking on bigger challenges
Table of Contents (21 chapters)
19
Other Books You May Enjoy
20
Index

Abstract classes using collections.abc

The abstract base classes (also known as interface classes) module is one of the most useful and most widely used examples of metaclasses in Python, as it makes it easy to ensure that a class adheres to a certain interface without a lot of manual checks. We have already seen some examples of abstract base classes in previous chapters, but now we will also look at their inner workings and some more advanced features, such as custom abstract base classes (ABCs).

Internal workings of the abstract classes

First, let’s demonstrate the usage of the regular abstract base class:

>>> import abc

>>> class AbstractClass(metaclass=abc.ABCMeta):
...     @abc.abstractmethod
...     def some_method(self):
...         raise NotImplemented()

>>> class ConcreteClass(AbstractClass):
...     pass

>>> ConcreteClass()
Traceback (most recent call last):
    ...
TypeError: Can't instantiate abstract class...