Find elements NOT in the intersection of two lists

Question

So I know how to find the intersection of two lists by doing:

>>> a = [1,2,3,4,5] >>> b = [1,3,5,6] >>> list(set(a) & set(b)) [1, 3, 5] 

But what is the best way to find all the elements that are not included in the intersection. My initial idea is to create a union of the two lists and then remove all the elements from the intersection from the union, as such:

>>> a = [1,2,3,4,5] >>> b = [1,3,5,6] >>> intersection = list(set(a) & set(b)) >>> union = list(set(a) | set(b)) >>> non_intersection = intersection - union [2, 4, 6] 

Is this the best way to do this or is there another way?

Answer 1

I usually prefer a shortcut:

set(a) ^ set(b) {2, 4, 6}