beginner <zyzhu2000 at gmail.com> writes: > For example, if I have x=[ [1,2], [3,4] ] > > What I want is a new list of list that has four sub-lists: > > [[1,2], [f(1), f(2)], [3,4], [f(3), f(4)]] [[a, map(f,a)] for a in x]