singleton ... again
Roy Smith
roy at panix.com
Wed Feb 12 00:55:59 EST 2014
In article <mailman.6728.1392183929.18130.python-list at python.org>,
Dave Angel <davea at davea.name> wrote:
> Asaf Las <roegltd at gmail.com> Wrote in message:
> > playing a bit with subject.
> >
> > pros and cons of this approach? did i create bicycle again? :-)
> >
> > class myclass(object):
> > class_instance = None
> >
> > def __new__(cls, *args, **kwargs):
> > if myclass.class_instance == None:
> > return object.__new__(cls)
> > return myclass.class_instance
> >
> > def __init__(self, some):
> > if self.__class__.class_instance == None: # init blocker
> > self.__class__.class_instance = self
> > self.member = some
> >
> > def __del__(self):
> > self.__class__.class_instance = None
> >
> > one_class = myclass(1)
> > print(id(one_class), one_class.member )
> >
> > two_class = myclass(2)
> > print(id(two_class), two_class.member)
> >
> >
>
> Perhaps if you would state your actual goal, we could judge
> whether this code is an effective way to accomplish
> it.
It looks to me like he's trying to implement a classic Gang of Four
singleton pattern.
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