Robust Python

Chapter 19. Pluggable Python

The greatest challenge in building a robust codebase is predicting the future. You will never completely guess what a future developer will do. The best strategy is not being perfectly prescient, but instead creating flexibility so that future collaborators can hook into your system with minimal work. In this chapter, I will focus on creating pluggable code. Pluggable code allows you to define behaviors that are to be supplied later. You define a framework with extension points, or parts of your system that other developers will use to extend functionality.

Think about a stand mixer sitting on a kitchen counter. You can select a variety of attachments to use with your mixer: a hook for mixing bread, a whisk for beating eggs and cream, and a flat beater to do general-purpose mixing. Each attachment serves a specific purpose. What’s great is that you can detach and attach hooks or blades as the situation calls for it. You don’t need to buy an entire new mixer for each use case; you plug in whatever you need when you need it.

This is the goal for pluggable Python. You don’t need to rebuild entire applications when new functionality is needed. You build extensions or attachments that snap onto a solid foundation. You pick the functionality you need for your specific use case and you plug that into your system.

In most of this book, I’ve been illustrating examples with automated food makers of some sort or another. In this chapter, I will perform the mother ...