Can you explain the decorator and adapter design patterns with examples?

Can you explain the decorator and adapter design patterns with examples?

Sure! The decorator pattern allows behavior to be added to individual objects, either statically or dynamically, without affecting the behavior of other objects from the same class. For example, if you have a Coffee class, you can create a MilkDecorator that adds milk to the coffee.

That sounds interesting! How does the adapter pattern work?

The adapter pattern allows incompatible interfaces to work together. It acts as a bridge between two incompatible interfaces. For instance, if you have a Bird interface and a Duck class, you can create a BirdAdapter that allows the Duck to be used where a Bird is expected.

Can you give me a code example for both patterns?

Absolutely! For the decorator pattern, you might have:

class Coffee:
    def cost(self):
        return 5

class MilkDecorator:
    def __init__(self, coffee):
        self._coffee = coffee

    def cost(self):
        return self._coffee.cost() + 1

And for the adapter pattern:

class Bird:
    def fly(self):
        pass

class Duck:
    def quack(self):
        print('Quack!')

class BirdAdapter(Bird):
    def __init__(self, duck):
        self.duck = duck

    def fly(self):
        self.duck.quack()

Thanks! How do I decide which pattern to use?

Great question! Use the decorator pattern when you want to add responsibilities to objects dynamically. Use the adapter pattern when you need to integrate incompatible interfaces.