Index of an item in a QuerySet

[samuel]

Hi all,

I'm probably just not seeing it, but how do I go about getting the
index of an item in a query set? I.E., this article is the Xth article
in this queryset of articles sorted by date.

Thanks,
Sam

[James Bennett]

If you're looping through them in the template with the 'for' tag,
each time through the loop you'll have access to a variable called
'forloop.counter' which has this information; the first time through
it will be 1, the second time it will be 2, and so on.

See http://www.djangoproject.com/documentation/templates/#for for details.

--
"May the forces of evil become confused on the way to your house."
-- George Carlin

[samuel]

> > I'm probably just not seeing it, but how do I go about getting the
> > index of an item in a query set? I.E., this article is the Xth article
> > in this queryset of articles sorted by date.
>
> If you're looping through them in the template with the 'for' tag,
> each time through the loop you'll have access to a variable called
> 'forloop.counter' which has this information; the first time through
> it will be 1, the second time it will be 2, and so on.
>
> See http://www.djangoproject.com/documentation/templates/#for for details.
>

Thanks but I guess I'm looking for something a bit different. Here's
exactly what I'm trying to do: I have articles that are chunked into
groups of 10 arbitrarily based on their date. So when a new article is
added the groups change. When you go to an article page, I want to
display the chunk that the article belongs to. So if the article is
19th, display a list of articles 11-20.

If I'm thinking through this correctly, I need to know the articles
location in the queryset before I get to the template and then slice
the queryset as necessary. How would I go about this? Just iterate
through and backtrack when I get there?

Thanks,
Sam

[Gábor Farkas]

if the number of articles is not too high, then simply generate their
number in the view... like:

queryset = Article.objects.all()

items = list(enumerate(queryset))

which is basically the same as:

items = zip (range(queryset.count()), queryset)

or, if you want it 1-based and not 0-based:

items = zip (range(1,queryset.count()+1), queryset)

the problem with these is that it fetches all the article-objects.

gabor

[Frankie Robertson]

Since the only way to do this is programmatically in python it might
be better to use raw sql for this instead.

>
> gabor
>
> >
>

--
http://grimboy.co.uk

[Gábor Farkas]

hmm.. how?

gabor

[Frankie Robertson]

Oh, I didn't really read the question carefully enough. You're right,
I don't think there is a standard SQL function to do this. The above
solution is pretty good. It could be done without having to fetch them
all.

Something like (obviously this could be less messy):

page = 1
queryset = Article.order_by('-pub_date')[(page-1)*10:page*10-1]
items = zip(range((page-1)*10+1, queryset.count()+1), queryset)

>
> gabor
>
> >
>

--
http://grimboy.co.uk