Confused again

[Duncan Smith]

I'm still (again) having a little trouble with operator overloading.  I
changed the original code I posted yesterday (Confusing problem) so that it
now (apparently) does what I want.  I simply changed "def __cmp__(self,
other):" to "def __eq__(self, other):".  But if I try to raise an exception
after calling the function, the exception is apparently ignored.  eg. the
following code snippet,

        print table == numtable2
        if table == numtable2:
            to_remove.append(table)
        else:
            print 'what?'
            raise Error

class Error:
    pass


>>> c.clusters[(3,)].pruneTables()
0                                # evaluates to false as expected
what?                         # prints 'what?' OK
>>>                           # but no error

I know this will be something I should know, or should have figured out for
myself.  But I just don't see it.  Any help appreciated.  Cheers.

Duncan