a[::-1] # all items in the array, reversed
a[1::-1] # the first two items, reversed
a[:-3:-1] # the last two items, reversed
a[-3::-1] # everything except the last two items, reversed
a[start:stop:step] # start through not past stop, by step
a[-1] # last item in the array
a[-2:] # last two items in the array
a[:-2] # everything except the last two items