Python enumerate reverse index only

Question

I am trying to reverse the index given by enumerate whilst retaining the original order of the list being enumerated.

Assume I have the following:

Answer 1

If you're going to re-use it several times, you can make your own generator:

def reverse_enum(lst):
    for j, item in enumerate(lst):
        yield len(lst)-1-j, item

print list(reverse_enum(range(5)))
# [(4, 0), (3, 1), (2, 2), (1, 3), (0, 4)]

or

def reverse_enum(lst):
    return ((len(lst)-1-j, item) for j, item in enumerate(lst))