How to pass queryset with exclude param in django-filter extension
<p>I'm using <a href="http://django-filter.readthedocs.io/en/latest/index.html" rel="nofollow">django-filter</a> and <a href="https://github.com/jamespacileo/django-pure-pagination" rel="nofollow">django-pure-pagination</a> extensions</p>

<pre><code>class BuyFilterView(PaginationMixin, FilterView):
    filterset_class = ProductFilter
    template_name = "buy_filter.html"
    context_object_name = "goods"
    paginate_by = 50

    def get_context_data(self, **kwargs):
        context = super(BuyFilterView, self).get_context_data(**kwargs)
        context['cart'] = Cart.objects.get(user=self.request.user)
        return context


class ProductFilter(FilterSet):
    country = ChoiceFilter(choices=country_values)
    brand = ChoiceFilter(choices=brand_values)
    type = ChoiceFilter(choices=type_values)

    class Meta:
        model = Goods
        fields = {
            'country': ['exact'],
            'brand': ['exact'],
            'type': ['exact'],
        }
</code></pre>

<p>Some items in <code>Goods</code> model have blank price value. I want to exclude them from queryset. How can I do this?</p>