设计模式-享元模式

例子1：
class Flyweight(object):
    def __init__(self, str):
        self.str = str

    def display(self):
        print("show the string: " + self.str)


class FlyweightFactory(object):
    def __init__(self):
        self.flyweights = {}  # 使用字典kye的唯一性实现享元

    def getFlyweight(self, obj):
        flyweight = self.flyweights.get(obj)
        if flyweight == None:
            flyweight = Flyweight(str(obj))
            self.flyweights[obj] = flyweight

    def showFlyweights(self):
        for i in self.flyweights:
            self.flyweights[i].display()
        print(len(self.flyweights))


if __name__ == "__main__":
    flyweightfactory = FlyweightFactory()
    flyweightfactory.getFlyweight("hello1")
    flyweightfactory.getFlyweight("hello1")
    flyweightfactory.getFlyweight("hello2")
    flyweightfactory.getFlyweight("hello2")
    flyweightfactory.getFlyweight("hello3")

    flyweightfactory.showFlyweights()
    
结果：
"""
show the string: hello1
show the string: hello2
show the string: hello3
3
"""