From 360e031f8d338b6be22ccd989473310864c454af Mon Sep 17 00:00:00 2001
From: Guido van Rossum <guido@python.org>
Date: Thu, 16 Aug 2001 15:42:49 +0000
Subject: [PATCH] I should add that the previous checkin also added a slight
 optimization for dynamic classes.  If __getattr__ is not found as an
 attribute on the type, slot_tp_getattro replaces itself with
 PyObject_GenericGetAttr.  This means you can't add a __getattr__ method to a
 class after the fact -- but you can still *change* a __getattr__ method into
 a different one.

(A similar restriction exists for classic classes.)