python-design-patterns

Composition over inheritance in Python favors building complex objects from smaller, focused components rather than deep class hierarchies. This design pattern reduces tight coupling and makes individual modules easier to swap, test, and maintain independently.

The single responsibility principle in Python modules ensures each class or function has only one reason to change. Applying this design pattern alongside KISS keeps functions small, isolates business logic, and makes the codebase easier to understand and test.

Introduce abstractions in Python architecture when you need to isolate business logic or simplify testing across tangled modules. Using the Rule of Three helps decide when to extract shared logic into clear API, service, and repository layers to reduce complexity.

The best way to refactor a monolithic Python request handler is to split it into clear API, service, and repository layers. This design pattern applies separation of concerns and dependency injection to isolate business logic and simplify testing.

Yes, this Python design pattern approach works for evaluating existing libraries by analyzing when to use composition, inheritance, or abstractions in services. It provides actionable guidelines like KISS and function sizing to assess maintainability and reduce coupling.