flyweight patterb属于结构设计模式类别.它提供了一种减少对象数量的方法.它包括各种有助于改进应用程序结构的功能. flyweight对象最重要的特性是不可变的.这意味着一旦构造它们就不能被修改.该模式使用HashMap存储引用对象.
如何实现flyweight模式？
以下程序有助于实现flyweight模式 :
class ComplexGenetics(object): def __init__(self): pass def genes(self, gene_code): return "ComplexPatter[%s]TooHugeinSize" % (gene_code)class Families(object): family = {} def __new__(cls, name, family_id): try: id = cls.family[family_id] except KeyError: id = object.__new__(cls) cls.family[family_id] = id return id def set_genetic_info(self, genetic_info): cg = ComplexGenetics() self.genetic_info = cg.genes(genetic_info) def get_genetic_info(self): return (self.genetic_info)def test(): data = (('a', 1, 'ATAG'), ('a', 2, 'AAGT'), ('b', 1, 'ATAG')) family_objects = [] for i in data: obj = Families(i[0], i[1]) obj.set_genetic_info(i[2]) family_objects.append(obj) for i in family_objects: print "id = " + str(id(i)) print i.get_genetic_info() print "similar id's says that they are same objects "if __name__ == '__main__': test()输出
上述程序生成以下输出 :
