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Re: Dynamically determine base classes on instantiation

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On Thu, Aug 16, 2012 at 05:10:43PM +0200, Hans Mulder wrote:
> On 16/08/12 14:52:30, Thomas Bach wrote:
> > 
> > So, my question (as far as I can see it, please correct me if I am
> > wrong) is less of the "How do I achieve this?"-kind, but more of the
> > "What is a clean design for this?"-kind. My intuitive thought was that
> > the `merge' function should be a part of the object returned from `F'.
> 
> The misunderstanding is that you feel F should return an object with
> a 'merge' method and a varying abse type, while Steven and others
> think that F should be a function.

OK, then my design wasn't so bad in the first place. :)

I made a class `Model' which wraps the actual type and realized
`merge' and `F' (with a better name, though) as classmethods of
`Model' in order to tie together the stuff that belongs together. By
the way, another need I saw for this design was that

setattr(Model(), 'foo', {'bar': int})

works, whereas 

setattr(dict(), 'foo', {'bar': int}) 

raises an AttributeError (on Python 3.2). Could someone give me the
buzz word (or even an explanation) on why that is so?

     Thomas Bach

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Thread

Dynamically determine base classes on instantiation Thomas Bach <thbach@students.uni-mainz.de> - 2012-08-15 23:17 +0200
  Re: Dynamically determine base classes on instantiation Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-08-16 00:16 +0000
    Re: Dynamically determine base classes on instantiation Thomas Bach <thbach@students.uni-mainz.de> - 2012-08-16 14:52 +0200
      Re: Dynamically determine base classes on instantiation Hans Mulder <hansmu@xs4all.nl> - 2012-08-16 17:10 +0200
        Re: Dynamically determine base classes on instantiation Thomas Bach <thbach@students.uni-mainz.de> - 2012-08-16 18:54 +0200
          Re: Dynamically determine base classes on instantiation Richard Thomas <chardster@gmail.com> - 2012-08-16 10:03 -0700
            Re: Dynamically determine base classes on instantiation Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-08-16 17:49 +0000
              Re: Dynamically determine base classes on instantiation Richard Thomas <chardster@gmail.com> - 2012-08-17 04:50 -0700
                Re: Dynamically determine base classes on instantiation Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-08-17 14:53 -0400
                Re: Dynamically determine base classes on instantiation Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-08-18 01:44 +0000
                Re: Dynamically determine base classes on instantiation Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-08-18 11:36 +0100
          Re: Dynamically determine base classes on instantiation Richard Thomas <chardster@gmail.com> - 2012-08-16 10:03 -0700
            Re: Dynamically determine base classes on instantiation Thomas Bach <thbach@students.uni-mainz.de> - 2012-08-16 19:27 +0200
      Re: Dynamically determine base classes on instantiation Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-08-16 18:04 +0000
    Re: Dynamically determine base classes on instantiation Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-08-16 12:29 -0400
    Re: Dynamically determine base classes on instantiation Richard Thomas <chardster@gmail.com> - 2012-08-16 10:09 -0700
      Re: Dynamically determine base classes on instantiation Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-08-16 17:45 +0000
    Re: Dynamically determine base classes on instantiation Thomas Bach <thbach@students.uni-mainz.de> - 2012-08-16 19:18 +0200
      Re: Dynamically determine base classes on instantiation Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-08-16 18:08 +0000

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