tuples, index method, Python's design

[Carsten Haese]

On Tue, 2007-04-10 at 17:10 +0200, BJörn Lindqvist wrote:
> On 4/10/07, Carsten Haese <carsten at uniqsys.com> wrote:
> > i = p.index(current_player)
> > opponents = p[:i-1] + p[i+1:]
> >
> > An alternative is this:
> >
> > opponents = tuple(x for x in p if x is not current_player)
> >
> > You may disagree, but in my opinion, the alternative is better because
> > it is a more natural translation of the concept that the opponents of
> > the current player are all players that are not the current player.
> 
> Your alternative is wrong because it wont raise ValueError if
> current_player is not present in the tuple. Please revise your
> "solution."

You have a point. Here is my revised solution:

assert current_player in p
opponents = tuple(x for x in p if x is not current_player)

The added advantage is that AssertionError is better than IndexError for
conveying that a severe program bug has occurred.

-Carsten