Robust Python

Part III. Extensible Python

Robust code is maintainable code. In order to be maintainable, code must be easy to read, easy to check for errors, and easy to change. Parts I and II of this book focused on readability and error detection, but not necessarily how to extend or modify existing code. Type annotations and typecheckers provide confidence to maintainers when interacting with individual types, but what about larger changes in a codebase, such as introducing new workflows or switching out a key component?

Part III examines larger changes and shows you how to enable future developers to make them. You’ll learn about extensibility and composability, both core principles that improve robustness. You’ll learn how to manage dependencies, to make sure that simple changes don’t create a ripple effect of bugs and errors. You’ll then apply these concepts to architectural models, such as plug-in-based systems, reactive programming, and task-oriented programs.