#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""http://ginstrom.com/scribbles/2008/11/06/generic-adapter-class-in-python/"""
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{0}".format("!" * octane_level)
class Adapter(object):
"""
Adapts an object by replacing methods.
Usage:
dog = Dog
dog = Adapter(dog, dict(make_noise=dog.bark))
>>> objects = []
>>> dog = Dog()
>>> objects.append(Adapter(dog, make_noise=dog.bark))
>>> cat = Cat()
>>> objects.append(Adapter(cat, make_noise=cat.meow))
>>> human = Human()
>>> objects.append(Adapter(human, make_noise=human.speak))
>>> car = Car()
>>> car_noise = lambda: car.make_noise(3)
>>> objects.append(Adapter(car, make_noise=car_noise))
>>> for obj in objects:
... print('A {} goes {}'.format(obj.name, obj.make_noise()))
A Dog goes woof!
A Cat goes meow!
A Human goes 'hello'
A Car goes vroom!!!
"""
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, make_noise=dog.bark))
cat = Cat()
objects.append(Adapter(cat, make_noise=cat.meow))
human = Human()
objects.append(Adapter(human, make_noise=human.speak))
car = Car()
objects.append(Adapter(car, make_noise=lambda: car.make_noise(3)))
for obj in objects:
print("A {0} goes {1}".format(obj.name, obj.make_noise()))
if __name__ == "__main__":
main()
### OUTPUT ###
# A Dog goes woof!
# A Cat goes meow!
# A Human goes 'hello'
# A Car goes vroom!!!