Queryset - exclude one data over two

[Stéphane Manguette]

Hello;

I've a DBB with a lot of values which are recorded every 2 minutes (this cannot be changed).

I'm trying to get all values recorded over the last 24h

def dashboard(request):

version = version_global

end_range = datetime.now()

beg_range = end_range - timedelta(days=1)

chart = temp_db.objects.filter(date__gte=beg_range)

    last_entry = chart.latest('date')

return render(request, 'index.html', locals())

The following code works perfectly. The goal is to populate a Chart.js in index.html. Unfortunately, there is a lot to transmit making it long to charge. Since my chart is not mainly meant to show trends; I could skip one data over two. Is there a function do do so? 

Thanks a lot,

Stéphane

[C. Kirby]

You can use islice from itertools in this way

islice('ABCDEFG', 0, None, 2) --> A C E G

In your case you would replace 
chart = temp_db.objects.filter(date__gte=beg_range)

with
chart = [x for x in islice(temp_db.objects.filter(date__gte=beg_range), 0, None, 2)]


That will give you every other instance from your query set starting with the first

[Stéphane Manguette]

Thanks ! It works perfectly !