How can I "count from the back" in python lists?

list, python, python-2.5, string

Solution

print l[-2:]

Negative numbers count from the end.

>>> l = ['h','e','l','l','o']
>>> print l[-2:]
['l', 'o']
>>> print l[-5:]
['h', 'e', 'l', 'l', 'o']
>>> print l[-6:]
['h', 'e', 'l', 'l', 'o']
>>>

Problem

Say I have a list `l = ['h','e','l','l','o']` I want to be able to take the last two items and use them, but I don't know how long the list is(It's user input). So can't do `l[3:]` because what if the list is seven(or any number) items long instead of five? How can I count from the back of the list?

Original source