See on http://www.sagemath.org/doc/thematic_tutorials/tutorial-programming-python.html
From the section "Modifying lists: reverse, sort, ...":
L = [4,2,5,1,3]
L.reverse()
sage: [3, 1, 5, 2, 4]
However I see -- nothing.
print L.reverse()
gives 'None'. I am using Sage 5.8.