python-单例模式的实现

何为单例？单例：一个类可以创建多个对象，这些对象指向同一个地址

1. 通过重写__new__方法

class Singleton(object):    """单例"""    __instance = None    def __new__(cls, *args, **kwargs):        if cls.__instance == None:            cls.__instance = object.__new__(cls)        return cls.__instance

1. 使用装饰器实现

def singleton(cls, *args, **kwargs)    """单例"""    instances = {}    def getinstance():        if cls not in instances:            instances[cls] = cls(*args, **kwargs)        return instance[cls]    return getinstance@singletonclass MyClass(object):    pass