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Re: How to mix-in __getattr__ after the fact?

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Date Fri, 28 Oct 2011 14:14:34 -0400
Subject Re: How to mix-in __getattr__ after the fact?
From Jerry Hill <malaclypse2@gmail.com>
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On Fri, Oct 28, 2011 at 1:34 PM, dhyams <dhyams@gmail.com> wrote:
> If I call __getattr__ directly, as in bessie.__getattr__('foo'), it
> works as it should obviously; so the method is bound and ready to be
> called.  But Python does not seem to want to call __getattr__
> appropriately if I mix it in after the object is already created.  Is
> there a workaround, or am I doing something wrongly?

Python looks up special methods on the class, not the instance (see
http://docs.python.org/reference/datamodel.html#special-method-lookup-for-new-style-classes).

It seems like you ought to be able to delegate the special attribute
access from the class to the instance somehow, but I couldn't figure
out how to do it in a few minutes of fiddling at the interpreter.

-- 
Jerry

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Thread

How to mix-in __getattr__ after the fact? dhyams <dhyams@gmail.com> - 2011-10-28 10:34 -0700
  Re: How to mix-in __getattr__ after the fact? Jerry Hill <malaclypse2@gmail.com> - 2011-10-28 14:14 -0400
  Re: How to mix-in __getattr__ after the fact? Ethan Furman <ethan@stoneleaf.us> - 2011-10-28 11:20 -0700
  Re: How to mix-in __getattr__ after the fact? Lie Ryan <lie.1296@gmail.com> - 2011-10-29 13:26 +1100
    Re: How to mix-in __getattr__ after the fact? dhyams <dhyams@gmail.com> - 2011-10-31 05:01 -0700
      Re: How to mix-in __getattr__ after the fact? DevPlayer <devplayer@gmail.com> - 2011-11-01 22:50 -0700
      Re: How to mix-in __getattr__ after the fact? Lie Ryan <lie.1296@gmail.com> - 2011-11-08 15:17 +1100
        Re: How to mix-in __getattr__ after the fact? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-11-08 05:58 +0000
      Re: How to mix-in __getattr__ after the fact? Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2011-11-08 11:21 +0100

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