faif/python-patterns

Python-Patterns is a reference collection of software design patterns implemented in Python. Design patterns are reusable, named solutions to commonly recurring problems in software design, they represent best practices distilled from decades of experience, covering challenges like how to create objects flexibly, how to structure relationships between components, and how to coordinate behavior across a system. The collection is organized into several categories. Creational patterns deal with object creation, for example, the Factory pattern delegates the decision of which class to instantiate to a specialized function, while the Builder pattern constructs complex objects step by step. Structural patterns define how classes and objects are composed, for instance, the Adapter pattern makes two incompatible interfaces work together, and the Facade pattern provides a simplified front-end to a complex subsystem. Behavioral patterns handle communication between objects, the Observer pattern lets objects subscribe to events and get notified when something changes, and the Strategy pattern allows swapping out different algorithms at runtime. Each pattern comes as a short, runnable Python file with a docstring explaining the concept. The repository also includes a section on anti-patterns, common solutions that seem reasonable but cause problems in Python specifically, such as the Singleton, which is unnecessary because Python modules already behave as singletons. Someone would use this repository when learning software engineering principles, preparing for technical interviews, or wanting to see concise Python-idiomatic implementations of classic patterns rather than reading abstract descriptions. It serves as both a learning resource and a quick reference for experienced developers. The tech stack is plain Python, no frameworks or external libraries required, keeping each example self-contained and easy to run.