I want to combine elements in different lists.For example, here are 3 lists.list_a : [ 1,2,3 ]list_b : [ 4,5,6 ]list_c : [ 7,8 ]Selecting elements from list_b and list_c is mutually exclusive.  When including an element from list_b, I'd like to also include an element from list_bb; when including an element from list_c, I'd like to also include an element from list_cc.list_bb : [ 14,15,16 ]list_cc : [ 17,18 ]I wrote this code:global sum_list=[]for a in list_a:    for b in list_b:        for bb in list_bb:            sum_list.append([a,b,bb])for a in list_a:    for c in list_c:        for cc in list_cc:           sum_list.append([a,c,cc])Is there any better way to get the same result?
Produce product of lists
python;combinatorics;python 2.7