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Mastering Python 2E

You're reading from   Mastering Python 2E Write powerful and efficient code using the full range of Python's capabilities

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Product type Paperback
Published in May 2022
Last Updated in May 2022
Publisher Packt
ISBN-13 9781800207721
Length 710 pages
Edition 2nd Edition
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Author (1):
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Rick Hattem Rick Hattem
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Rick Hattem
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Table of Contents (21) Chapters Close

Preface 1. Getting Started – One Environment per Project FREE CHAPTER 2. Interactive Python Interpreters 3. Pythonic Syntax and Common Pitfalls 4. Pythonic Design Patterns 5. Functional Programming – Readability Versus Brevity 6. Decorators – Enabling Code Reuse by Decorating 7. Generators and Coroutines – Infinity, One Step at a Time 8. Metaclasses – Making Classes (Not Instances) Smarter 9. Documentation – How to Use Sphinx and reStructuredText 10. Testing and Logging – Preparing for Bugs 11. Debugging – Solving the Bugs 12. Performance – Tracking and Reducing Your Memory and CPU Usage 13. asyncio – Multithreading without Threads 14. Multiprocessing – When a Single CPU Core Is Not Enough 15. Scientific Python and Plotting 16. Artificial Intelligence 17. Extensions in C/C++, System Calls, and C/C++ Libraries 18. Packaging – Creating Your Own Libraries or Applications 19. Other Books You May Enjoy
20. Index

Automatically registering plugin systems

One very useful way to use metaclasses is to have classes automatically register themselves as plugins/handlers.

Instead of manually adding a register call after creating the class or by adding a decorator, you can make it completely automatic for the user. That means that the user of your library or plugin system cannot accidentally forget to add the register call.

Note the distinction between registering and importing. While this first example shows automatic registering, automatic importing is covered in later sections.

Examples of these can be seen in many projects such as web frameworks. The Django web framework, for example, uses metaclasses for its database models (effectively tables) to automatically generate the table and column names based on the class and attribute names.

The actual code base of projects like these is too extensive to usefully explain here though. Hence, we’ll show a simpler example...

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