Django:for循环中的总和值

Question

我想计算表单集中订单价格的总和。如何求和 int(food.price) * int(f.order_count) ？

def reservation_f(request, year, month, day):
    # order_count = Food.objects.filter(serve_date__startswith = datetime.date(int(year), int(month), int(day))).count()
    ReservationFormset = modelformset_factory(
        Reservation,
        extra = 1,
        fields = ('order_count', 'order_name', 'order_date'),
        form = Reserve,
        )
    if request.method == "POST":
        formset = ReservationFormset(request.POST, queryset=Food.objects.none(),
        form_kwargs={'month': month, 'year': year, 'day':day})
        if formset.is_valid():
            formset = formset.save(commit=False)
            for f in formset:
                food = Food.objects.get(
                    serve_date__startswith = datetime.date(int(year), int(month), int(day)),
                    food_name=f.order_name)
                print int(food.price) * int(f.order_count)
            for f in formset:
                f.user = request.user
                f.save()

        return HttpResponse("Add")
    else:
        formset = ReservationFormset(queryset=Food.objects.none(),
        form_kwargs={'month': month, 'year': year, 'day':day})
        return render(request, 'form.html', {'formset':formset})

Answer 1

你的变量的含义和类型不是很清楚，所以我可能是错的。但你可以做类似的事情:

for f in formset:
    food = Food.objects.get(
        se_date__startswith = datetime.date(int(year), int(month), int(day)),
        food_name=f.order_name)
    print sum([int(item.price) * int(f.order_count) for item in food])