Tutorial creates confusion about slices

Ant antroy at gmail.com
Wed Apr 25 17:15:39 EDT 2007

On Apr 23, 1:38 pm, Antoon Pardon <apar... at forel.vub.ac.be> wrote:
> The following is part of the explanation on slices in the
> tutorial:
> The best way to remember how slices work is
>   +---+---+---+---+---+
>   | H | e | l | p | A |
>   +---+---+---+---+---+
>   0   1   2   3   4   5
>  -5  -4  -3  -2  -1
> This is all very well with a simple slice like:
>   "HelpA"[2:4]    =>     "lp"
> But it give the wrong idea when using the following extended slice:
>   "HelpA"[4:2:-1]   =>   "Ap"

I think that the tutorial example is absolutely fine as it is. It
gives the new python programmer (the target demographic of the
tutorial) a visual tool to understand what simple slicing is. Extended
slicing (in particular ones using negative indices) are beyond the
scope of the tutorial, and thus are irrelevant as far as the example

Adding examples / memory aids to cover all the many varied and
possibly degenerate ways you can slice a string would merely confuse
the python newbie. By the time you actually *are* interested in the
more advanced slicing capabilities, it's time to read the Library
reference where the formula stating *exactly* how slicing works is

A tutorial has every reason to be simplistic, so as far as I'm
concerned, -1 for changing the docs.

Apologies if this turns out to be my third near identical post - I've
tried sending variations on this message twice already today from
Google Groups, and they seem to have got lost in the ether...

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