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Re:singleton ... again

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From Dave Angel <davea@davea.name>
Subject Re:singleton ... again
Date Wed, 12 Feb 2014 00:48:51 -0500 (EST)
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 Asaf Las <roegltd@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.


-- 
DaveA

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Thread

singleton ... again Asaf Las <roegltd@gmail.com> - 2014-02-11 20:34 -0800
  Re: singleton ... again Asaf Las <roegltd@gmail.com> - 2014-02-11 21:15 -0800
  Re:singleton ... again Dave Angel <davea@davea.name> - 2014-02-12 00:48 -0500
    Re: singleton ... again Roy Smith <roy@panix.com> - 2014-02-12 00:55 -0500
      Re: singleton ... again Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-02-12 23:04 +1300
        Re: singleton ... again Ben Finney <ben+python@benfinney.id.au> - 2014-02-12 21:09 +1100
          Re: singleton ... again Roy Smith <roy@panix.com> - 2014-02-12 08:40 -0500
          Re: singleton ... again Piet van Oostrum <piet@vanoostrum.org> - 2014-02-13 10:00 +0100
            Re: singleton ... again Ned Batchelder <ned@nedbatchelder.com> - 2014-02-13 06:50 -0500
            Re: singleton ... again Chris Angelico <rosuav@gmail.com> - 2014-02-13 22:57 +1100
              Re: singleton ... again Roy Smith <roy@panix.com> - 2014-02-13 10:24 -0500
                Re: singleton ... again Chris Angelico <rosuav@gmail.com> - 2014-02-14 07:03 +1100
                Re: singleton ... again Robert Kern <robert.kern@gmail.com> - 2014-02-13 21:13 +0000
                Re: singleton ... again Chris Angelico <rosuav@gmail.com> - 2014-02-14 08:27 +1100
            Re: singleton ... again Ethan Furman <ethan@stoneleaf.us> - 2014-02-13 08:57 -0800
              Re: singleton ... again Roy Smith <roy@panix.com> - 2014-02-13 12:57 -0500
                Re: singleton ... again Ethan Furman <ethan@stoneleaf.us> - 2014-02-13 10:31 -0800
                Re: singleton ... again Roy Smith <roy@panix.com> - 2014-02-13 14:03 -0500
                Re: singleton ... again Chris Angelico <rosuav@gmail.com> - 2014-02-14 06:50 +1100
                Re: singleton ... again Grant Edwards <invalid@invalid.invalid> - 2014-02-13 22:28 +0000
              Re: singleton ... again Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-02-14 18:21 +1300
            Re: singleton ... again Tim Delaney <timothy.c.delaney@gmail.com> - 2014-02-14 06:16 +1100
        Re: singleton ... again Steven D'Aprano <steve@pearwood.info> - 2014-02-13 02:58 +0000
          Re: singleton ... again Ben Finney <ben+python@benfinney.id.au> - 2014-02-13 14:07 +1100
            Re: singleton ... again Steven D'Aprano <steve@pearwood.info> - 2014-02-13 04:24 +0000
              Re: singleton ... again Chris Angelico <rosuav@gmail.com> - 2014-02-13 15:33 +1100
              Re: singleton ... again Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-02-14 18:15 +1300
          Re: singleton ... again Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-02-14 18:06 +1300
    Re: singleton ... again Asaf Las <roegltd@gmail.com> - 2014-02-12 09:50 -0800
      Re: singleton ... again Asaf Las <roegltd@gmail.com> - 2014-02-12 09:56 -0800
        Re: singleton ... again Asaf Las <roegltd@gmail.com> - 2014-02-12 09:58 -0800
        Re: singleton ... again Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-02-13 10:57 +1300
          Re: singleton ... again Asaf Las <roegltd@gmail.com> - 2014-02-12 17:38 -0800
      Re: singleton ... again Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-02-12 18:57 +0000
        Re: singleton ... again Asaf Las <roegltd@gmail.com> - 2014-02-12 17:02 -0800
      Re: singleton ... again Ned Batchelder <ned@nedbatchelder.com> - 2014-02-12 16:34 -0500
        Re: singleton ... again Asaf Las <roegltd@gmail.com> - 2014-02-12 17:34 -0800
      Re: singleton ... again Tim Delaney <timothy.c.delaney@gmail.com> - 2014-02-13 10:08 +1100
      Re: singleton ... again Roy Smith <roy@panix.com> - 2014-02-12 20:57 -0500
  Re: singleton ... again Michael Torrie <torriem@gmail.com> - 2014-02-12 15:05 -0700

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