How to access the low digits of a list

[Rustom Mody]

On Tuesday, June 2, 2015 at 7:50:58 PM UTC+5:30, Ian wrote:
> On Tue, Jun 2, 2015 at 6:35 AM, Rustom Mody  wrote:
> > For that matter even this works
> > But I am not sure whats happening or that I like it
> >
> >>>> [x[-2:]  for x in lines]
> > ['12', '42', '49', '56', '25', '36', '49', '64', '81', '00']
> 
> x[-2:] selects all items in the sequence with index i such that len(x)
> - 2 <= i < len(x). For a sequence of length 2 or less, that's the
> entire sequence.

Thanks -- learn something
So it means that indices can give indexerror; slices cannot?
Seems fair enough put that way, but is visually counterintuitive