Python method resolution mystery

Question

I can't figure out why this program is failing.

#!/usr/bin/env python
from __future__ import division, print_function
from future_builtins import *
import types
import libui as ui
from PyQt4 import QtCore
import sip

p = ui.QPoint()
q = QtCore.QPoint()

def _q_getattr(self, attr):
    print("get %s" % attr)
    value = getattr(sip.wrapinstance(self.myself(), QtCore.QPoint), attr)
    print("get2 %s returned %s" % (attr, value))
    return value

p.__getattr__ = types.MethodType(_q_getattr, p)

print(p.__getattr__('x')())  # Works!  Prints "0"
print(p.x())  # AttributeError: 'QPoint' object has no attribute 'x'

I used Boost.Python to create libui, which exposes the class QPoint. I aso included PyQt4, which has a sip-exposed QPoint. I'm trying to accomplish a mapping between the two types.

I checked that p is a new-style class, so why isn't __getattr__ being called for p.x()?