singleton.py �Eb�U �Q;a�U import threading # Based on tornado.ioloop.IOLoop.instance() approach. # See https://github.com/facebook/tornado class SingletonMixin(object): __singleton_lock = threading.Lock() __singleton_instance = None @classmethod def instance(cls): if not cls.__singleton_instance: with cls.__singleton_lock: if not cls.__singleton_instance: cls.__singleton_instance = cls() return cl
![A thread safe implementation of singleton pattern in Python. Based on tornado.ioloop.IOLoop.instance() approach.](https://cdn-ak-scissors.b.st-hatena.com/image/square/1ef26f6cb4349557952890dbe3e567f7f98dc151/height=288;version=1;width=512/https%3A%2F%2Fgithub.githubassets.com%2Fassets%2Fgist-og-image-54fd7dc0713e.png)