[docs] Python doc bug?

[Georg Brandl]

Hi David,

you can call the second index the "end-index", but the thing to remember is
that it is never included.  You can imagine the indices being "between" the
items, like this:

x = | a | b | c | d | e |
     0   1   2   3   4   5
    -5  -4  -3  -2  -1

so x[1:3] is [b, c] and x[1:-1] is [b, c, d].

cheers,
Georg

On 06.03.2012 03:28, David Arendash wrote:
> http://docs.python.org/tutorial/introduction.html#lists
>
> I’m new to Python, so I’m trying to understand this list index stuff, but it
> looks to me like:
>
> *>>>  *a  =  ['spam',  'eggs',  100,  1234]
>
> *>>>  *a
>
> ['spam', 'eggs', 100, 1234]
>
> Like string indices, list indices start at 0, and lists can be sliced,
> concatenated and so on:
>
>> >>
>
> *>>>  *a[0]
>
> 'spam'
>
> *>>>  *a[3]
>
> 1234
>
> *>>>  *a[-2]
>
> 100
>
> *>>>  *a[1:-1]
>
> ['eggs',*100*]    Shouldn’t that last item be 1234?
>
> *>>>  *a[:2]  +  ['bacon',  2*2]
>
> ['spam', 'eggs', 'bacon', 4]    Isn’t [:2] to mean‘from start (0) to 2, thus first 3 elements, so should be 100 between eggs an bacon?
>
> *>>>  *3*a[:3]  +  ['Boo!']
>
> ['spam', 'eggs', 100, 'spam', 'eggs', 100, 'spam', 'eggs', 100, 'Boo!']Doesn’t [:3] mean‘from 0 to 3’  thus 4 items should be repeated?
>
> It looks like whoever wrote this intended the number after the colon to mean
> ‘count’, but according to this: http://www.korokithakis.net/tutorials/python/
>
> the number after the colon is the end-index. If it were the count, the first
> line I’ve highlighted would make no sense at all.