The adapter pattern is often used in programming when you need to adapt one interface to another. Here's a simple generic adapter class that can adapt just about any interface to just about any other.
class Adapter(object): """ Adapts an object by replacing methods. Usage: dog = Dog() dog = Adapter(dog, dict(make_noise=dog.bark)) """ def __init__(self, obj, adapted_methods): """We set the adapted methods in the object's dict""" self.obj = obj self.__dict__.update(adapted_methods) def __getattr__(self, attr): """All non-adapted calls are passed to the object""" return getattr(self.obj, attr)
This adapter can be used to adapt many objects with different interfaces into a single, unified interface.
import os class Dog(object): def __init__(self): self.name = "Dog" def bark(self): return "woof!" class Cat(object): def __init__(self): self.name = "Cat" def meow(self): return "meow!" class Human(object): def __init__(self): self.name = "Human" def speak(self): return "'hello'" class Car(object): def __init__(self): self.name = "Car" def make_noise(self, octane_level): return "vroom%s" % ("!" * octane_level) class Adapter(object): """ Adapts an object by replacing methods. Usage: dog = Dog dog = Adapter(dog, dict(make_noise=dog.bark)) """ def __init__(self, obj, adapted_methods): """We set the adapted methods in the object's dict""" self.obj = obj self.__dict__.update(adapted_methods) def __getattr__(self, attr): """All non-adapted calls are passed to the object""" return getattr(self.obj, attr) def main(): objects = [] dog = Dog() objects.append(Adapter(dog, dict(make_noise=dog.bark))) cat = Cat() objects.append(Adapter(cat, dict(make_noise=cat.meow))) human = Human() objects.append(Adapter(human, dict(make_noise=human.speak))) car = Car() car_noise = lambda : car.make_noise(3) objects.append(Adapter(car, dict(make_noise=car_noise))) for obj in objects: print "A", obj.name, "goes", obj.make_noise() if __name__ == "__main__": main()
Output:
A Dog goes woof! A Cat goes meow! A Human goes 'hello' A Car goes vroom!!!
python 适配器模式 更详细具体的描述:
http://ginstrom.com/scribbles/2009/03/27/the-adapter-pattern-in-python/