[Tutor] working with empty lists

[Rance Hall]

On Thu, Sep 16, 2010 at 9:24 AM, Joel Goldstick
<joel.goldstick at gmail.com> wrote:
> I typed in this:
>
>
>   3 l = []
>   4
>   5 for i in range(0,10):
>   6     l.append(i+1)
>   7
>   8 for i in range(0,10):
>   9     print ('%s. %s' % (i, l[i]))
>  10
>  11 def paginate_stuff(list, start):
>  12     pagesize = 2
>  13     for i in list[start:start+pagesize]:
>  14         print ('%s. %s' % (i,list[i]))
>  15     return
>  16
>  17 paginate_stuff(l,0)
>
> and i get this:
> 0. 1
> 1. 2
> 2. 3
> 3. 4
> 4. 5
> 5. 6
> 6. 7
> 7. 8
> 8. 9
> 9. 10
> 1. 2
> 2. 3
>
>
> What are you expecting?
>
>

you are getting what I am getting, so good news there, its not my code
(its my understanding instead)

In the above output where the you go from 9. 10 and the next item is 1. 2

I'm expecting the next item to be 0. 1 again.

It appears as if the for loop iterator is iterating BEFORE it executes
stuff as opposed to after like I'm used to.

if I change the print line inside the for loop to:

print('%s. %s) % (i-1,list[i-1]))

I get what I think I should have gotten orginally

Is this the correct understanding, is the for loop iterator iterating
before any of the stuff executes the first time?  This seems odd to me
somehow.

I appear to have fixed it, now I just wish I understood it.

R