Python 单例模式

  # 单例模式
class Boss(object):
    __instance = None
    __first = False
    def __new__(cls, *args, **kwargs):
        if not cls.__instance:
            cls.__instance = object.__new__(cls)
        return cls.__instance

    def __init__(self, name):
        if not self.__first:
            self.name = name
            self.__first = True