How can I count from the back in python lists

Question

Say I have a list
l = ['P','y','t','h','o','n']

I want to be able to use the last two items, but I'm not sure how long the list is because it was user-generated.

Therefore, it is impossible to do l[3:] because what if the list has seven (or any other number) entries instead of five?

How do I count backward from the list's back?

Answer 1

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']
>>>