from PySide.QtCore import *
from PySide.QtGui import *

class App(QApplication):
    def __init__(self,*args):
        super(App,self).__init__(*args)
    def notify(self,r,e):
        QApplication.notify(self,r,e)
        return None  # deliberately wrong

import sys
app = App(sys.argv)
QWidget()


results in exceptions:

Traceback (most recent call last):
  File "<stdin>", line 8, in notify
TypeError: Invalid return value in function QApplication.notify, expected bool,
got NoneType.
Traceback (most recent call last):
  File "<stdin>", line 13, in <module>
SystemError: NULL result without error in PyObject_Call


This isn't as bad as it looks because the first exception already explains what
the user should fix, but the second exception doesn't look good.