On Wed, 04 Jul 2007 16:18:58 +0200, Thomas Jollans wrote: > On Wednesday 04 July 2007, David Abrahams wrote: >> Right now, the only convenient thing to do is >> >> if s1 & s2 ... >> >> but that builds a whole new set. IMO that query should be available >> as a method of set itself. > >>>> s1 = set(xrange(5)) >>>> s2 = set(xrange(3,9)) >>>> s1 > set([0, 1, 2, 3, 4]) >>>> s2 > set([3, 4, 5, 6, 7, 8]) >>>> s1 | s2 > set([0, 1, 2, 3, 4, 5, 6, 7, 8]) >>>> s1 & s2 > set([3, 4]) >>>> > > It's all in python already. And documented on the web too.
The OP already knows that but does not want to build a new `set`. He just wants to know efficiently if the sets intersect without actually *doing* the intersection. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list