Python Singleton

gistfile1.py

## Metaclass for singletons

class Singleton(type):
    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

## Real instance ...

class MySingleton(object):
    __metaclass__ = Singleton

    pass