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From: Terry Reedy <tjreedy@udel.edu>
Subject: Re: data attributes override method attributes?
Date: Fri, 28 Sep 2012 14:26:05 -0400
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On 9/28/2012 2:02 PM, Prasad, Ramit wrote:

> Just to make sure I am following, if you call
> foo.__len__() it goes to the instance code while
> if you do len(foo) it will go to class.__len__()?

len(foo) calls someclass.__len__(foo) where someclass is foo.__class__or 
some superclass.

> If so, why?

Efficiency and perhaps simpler implementation, especially for binary ops.

-- 
Terry Jan Reedy