Newbie: The philosophy behind list indexes

[Olive]

On 15/06/13 07:21, ian.l.cameron at gmail.com wrote:
>
> I bet this is asked quite frequently, however after quite a few hours searching I haven't found an answer.
>
> What is the thinking behind stopping 'one short' when slicing or iterating through lists?
>
> By example;
>
>>>> a=[0,1,2,3,4,5,6]
>>>> a
> [0, 1, 2, 3, 4, 5, 6]
>>>> a[2:5]
> [2, 3, 4]
>
> To my mind, it makes more sense to go to 5. I'm sure there's a good reason,
> but I'm worried it will result in a lot of 'one-off' errors for me, so I need to get my head around the philosophy
> of this behaviour, and where else it is observed (or not observed.)

I think it simplify some arithmetic. How many element contain a[2:5]? 
Answer 5-2=3. And a[:5] contain the first 5 elements.

Olive