python单例的使用详解

class MusicPlayer(object):

    # 定义类属性记录单例对象引用

    instance = None

    def __new__(cls, *args, **kwargs):

        # 1. 判断类属性是否已经被赋值

        if cls.instance is None:

            cls.instance = super().__new__(cls)

        # 2. 返回类属性的单例引用

        return cls.instance