[magnus@gills magnus]$ python2.2
Python 2.2 (#1, Jan 26 2002, 14:27:24)
[GCC 2.96 20000731 (Red Hat Linux 7.1 2.96-98)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> class foo(object):
...     pass
...
>>> raise foo()
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
TypeError: exceptions must be strings, classes, or instances, not foo
>>>