On Apr 28, 11:16 pm, Arnaud Delobelle <arno...@googlemail.com> wrote: > Kay Schluehr <kay.schlu...@gmx.net> writes: > > On 29 Apr., 05:41, Ross <ross.j...@gmail.com> wrote: > >> If I have a list x = [1,2,3,4,5,6,7,8,9] and another list that is a > >> subset of x: y = [1,4,7] , is there a quick way that I could return > >> the complementary subset to y.... z=[2,3,5,6,8,9] ? > > >> The reason I ask is because I have a generator function that generates > >> a list of tuples and I would like to divide this list into > >> complementary lists. > > > z = [u for u in x if u not in y] > > > or > > > z = [u for u in x if u not in set(y)] > > The above will evaluate set(y) for each element in x. > > s = set(y) > z = [u for u in x if u not in s] > > -- > Arnaud
>>>y = [1, 2, 3, 4, 5] >>>s = set(y) >>>s.complimentary() ['you are handsome', 'you are smart', 'nice jacket'] -- http://mail.python.org/mailman/listinfo/python-list
