1.工厂模式

from abc import ABC, abstractmethod

class Fruit(ABC):

    def __init__(self):
        self.name = None

    @abstractmethod
    def eat(self):
        pass

class Apple(Fruit):

    def __init__(self):
        self.name = "Apple"

    def eat(self):
        print("emmm, I'm an %s" % self.name)


class Banana(Fruit):

    def __init__(self):
        self.name = "Banana"

    def eat(self):
        print("Ouch, you cannot eat a %s" % self.name)


class Orange(Fruit):

    def __init__(self):
        self.name = "Orange"

    def eat(self):
        print("I'm an %s and very sour" % self.name)


class FruitFactory(object):

    @staticmethod
    def getFruit(name):
        assert type(name) in [str]
        fruit_clss = {
            "apple": Apple,
            "banana": Banana,
            "orange": Orange
        }
        fruit_cls = fruit_clss.get(name.lower())
        if fruit_cls:
            return fruit_cls()
        else:
            raise Exception("I cannot produce the fruit named %r" % name)



if __name__ == "__main__":
    fruit = FruitFactory.getFruit('apple')
    fruit.eat()