TWIG::2020.07.20

- Singleton

• https://stackoverflow.com/questions/6760685/creating-a-singleton-in-python
• https://python-3-patterns-idioms-test.readthedocs.io/en/latest/Singleton.html
• https://github.com/Kemaweyan/singleton_decorator

how to implement singleton in python?
there is really lot of way to do. even there is a library.
(even if this library's last update is 3 years ago...)

this moment i do not fully understand those codes.
but i need to implement code. so i choose some alternative.

...
    _instance = None

    @classmethod
    def _getInstance(cls):
        return cls._instance

    @classmethod
    def instance(cls, *args, **kargs):
        cls._instance = cls(*args, **kargs)
        cls.instance = cls._getInstance

        return cls._instance
...

this code has critical cons that is can not use constructor. so i just call __init__like method once.

    @classmethod
    def init_like(cls):
        # initialize instance
        pass

i know this is bad. and quite ugly ☹️
so i refactor this part later.

- Guide

• https://wikidocs.net/3693
• https://yamalab.tistory.com/75?category=719677

- Oh my AWS

• https://sanghaklee.tistory.com/32