Don't work __getattr__ with __add__

Chris Rebert clp2 at rebertia.com
Thu Mar 4 09:38:58 CET 2010


On Thu, Mar 4, 2010 at 12:25 AM, Андрей Симурзин <asimurzin at gmail.com> wrote:
> It is object of the class A, in conteiner's class tmpA. Not all method
> from A are in the tmpA. So for exapmle:
> A + B -- yes , tmpA + B no. I try to call method from A for tmpA. I
> can to call simple method,  such as change(), bit __add__ -  don't
> work. If to remove inheritance from object, the code work's. Help me,
> please

Some clarity has been lost in translation, but I think I get what you're saying.
__add__ and the other double-underscore special methods are not looked
up using __getattr__ or __getattribute__, hence trying to do addition
on tmpA, which does not define an __add__ method, fails.

For a full explanation, read:
http://docs.python.org/reference/datamodel.html#special-method-lookup-for-new-style-classes

Cheers,
Chris
--
http://blog.rebertia.com



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