Design Patterns

A design pattern is a named, reusable solution to a recurring design problem. One of the most common in Python:

class DatabaseConnection:
    _instance = None

    @classmethod
    def get_instance(cls):
        if cls._instance is None:
            cls._instance = cls()
        return cls._instance

This is the Singleton pattern — guaranteeing only one instance of a class ever exists (useful for something like a single shared database connection). Patterns are a shared vocabulary between developers, not a checklist to force into every project.