Intermediate

Design Patterns in Python

Design patterns are reusable solutions to common software problems. They improve code readability and maintainability.

Singleton Pattern

class Singleton:
    _instance = None
    def __new__(cls):
        if not cls._instance:
            cls._instance = super().__new__(cls)
        return cls._instance

Factory Pattern

def factory(shape):
    if shape == "circle":
        return "Circle created"

Observer Pattern

✔ Used in event systems
✔ GUI frameworks
✔ Messaging apps

📝 Practice: Implement a simple Factory pattern.

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