Nick Coghlan wrote: > A discussion on the py3k list reminded me that translating a forward slice > into a reversed slice is significantly less than obvious to many people. Not > only do you have to negate the step value and swap the start and stop values, > but you also need to subtract one from each of the step values, and ensure > the > new start value was actually in the original slice: > > reversed(seq[start:stop:step]) becomes > seq[(stop-1)%abs(step):start-1:-step] > > An rslice builtin would make the latter version significantly easier to read: > > seq[rslice(start, stop, step)]
Or slice.reversed(). -- David Hopwood <[EMAIL PROTECTED]> _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
