python 单例模式

class MusicPlayer(object):
    """单例模式"""

    instance = None
    flag_init = False

    def __new__(cls, *args, **kwargs):
        """单例模式实现"""
        if cls.instance is None:
            cls.instance = super().__new__(cls)
            print("New")
        return cls.instance
    
    def __init__(self):
        # 每次都会初始化
        #print("init")
        
        # 只初始化1次
        if MusicPlayer.flag_init == False:
            MusicPlayer.flag_init = True
            print("init")
        return


if __name__ == '__main__':
    player1 = MusicPlayer()
    player2 = MusicPlayer()