On Aug 15, 11:51 pm, Laszlo Nagy <gand...@shopzeus.com> wrote: > >> hi list, > >> what is the best way to check if a given list (lets call it l1) is > >> totally contained in a second list (l2)? > > >> for example: > >> l1 = [1,2], l2 = [1,2,3,4,5] -> l1 is contained in l2 > >> l1 = [1,2,2,], l2 = [1,2,3,4,5] -> l1 is not contained in l2 > >> l1 = [1,2,3], l2 = [1,3,5,7] -> l1 is not contained in l2 > > >> my problem is the second example, which makes it impossible to work with > >> sets insteads of lists. But something like set.issubset for lists would > >> be nice. > > >> greatz Johannes > > Fastest, error-free and simplest solution is to use sets: > > >>> l1 = [1,2] > >>> l2 = [1,2,3,4,5] > >>> set(l1)-set(l2) > set([]) > >>> set(l2)-set(l1) > set([3, 4, 5]) > >>> >
This approach fails the OP's desires when >>> l1 = [1,2,2,] >>> l2 = [1,2,3,4,5] The OP explicitly desires 'l2 contains l1' to be false in that case. Cheers - Chas -- http://mail.python.org/mailman/listinfo/python-list