def chart(request):
dataset = Evenement.objects.annotate(Day=TruncDay('date_Evt')).values('Day','from_office')\
.annotate(depot=Count('from_office',filter=Q(status='déposé')),
affecte=Count('from_office',filter=Q(status='affecté')),
livre=Count('from_office',filter=Q(status="livré")),
taux=F('livre')/F('affecte')).all()
return render(request, 'charts_event_list.html', {'dataset':dataset} )