Carl Banks wrote: > Ron Adam wrote: >> Carl Banks wrote: >> >>> In Python, yes and no are the only possible answers. Probably the only >>> analogous thing you could do in Python would be for all() to raise >>> ValueError when passed an empty sequence. >> There is also 'None' which serves a similar purpose of indicating an >> invalid value when passing arguments. > > If all() were to return None, then if would essentially be like > returning False, because an if-statement would treat False and None the > same (as would most anything else expecting a boolean value). > > The only reasonable way to say "false assumption" in Python is to raise > an exception. > > > Carl Banks
Then maybe None should be evaluated as True so it is consistent with all(). ;-) Not serious of course, Cheers, Ron -- http://mail.python.org/mailman/listinfo/python-list