# -*- coding: utf-8 -*-

# https://wikidocs.net/3693

__all__ = (

'Singleton'

)

class Singleton(type):

"""

상속용 싱글턴

"""

def __init__(cls, name, bases, dict):

super(Singleton, cls).__init__(name, bases, dict)

cls.instance = None

def __call__(cls, *args, **kw):

if cls.instance is None:

cls.instance = super(Singleton, cls).__call__(*args, **kw)

return cls.instance

class SingletonInheritance(type):

"""

상속용 싱글턴 2

"""

_instances = {}

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

if cls not in cls._instances:

cls._instances[cls] = super(SingletonInheritance, cls).__call__(*args, **kwargs)

return cls._instances[cls]

def singleton_decorator(class_):

"""

데코레이터용 싱글턴, siaticMethod 접근 불가

"""

instances = {}

def getinstance(*args, **kwargs):

if class_ not in instances:

instances[class_] = class_(*args, **kwargs)

return instances[class_]

return getinstance