pythonic way to sort a list of lists by the last item of the inner list

Question

I have a list like this

[[x,y,1],[w,u,4],[m,n,3] ... [p,q,5]]

I need to sort the outer list by the third (last) element of the inner list, the

Answer 1

my_list.sort(key=lambda x: x[-1])

or

my_list.sort(key=operator.itemgetter(-1))

The second option is slightly faster.