python - How to filter out objects from Django Rest serializer based on Foreign key set criteria -

i'm using django rest framework , got stuck.

i have 3 models, follows.

class store(models.model):     name = models.charfield(unique=true, max_length=255)     ...     is_valid = models.integerfield(default=0)     ...  class category(models.model):     category = models.charfield(max_length=255, unique=true)     importance = models.integerfield(default=0, null=true)   class storecategory(models.model):     store = models.foreignkey(store)     category = models.foreignkey(category) 

for rest framework these serializers have:

class storecategoryserializer(serializers.modelserializer):     store = storeserializer(read_only=true)     class meta:         model = storecategory         fields = ('store', )  class allstoreserializer(serializers.modelserializer):     # stores = storecategoryserializer(source="storecategory_set", many=true)     stores = serializers.serializermethodfield('get_stores_list')      def get_stores_list(self, obj):         scs = obj.storecategory_set.exclude(store__is_valid=0).order_by('store__id')         serializer = storecategoryserializer(scs, many=true)         return serializer.data      class meta:         model = category         fields = ('id', 'category', 'stores') 

view follows:

class allstores(apiview):     def get(self, request):         categories = category.objects.all().order_by('-importance')         serializer = allstoreserializer(categories, many=true)         return response(serializer.data) 

now, problem is, want return categories there stores is_valid != 0. i.e. if stores list category has 0 elements, category not included in data returned(data returned api). id storecategory_set has size equal 0, not include category. how can this?

thanks :)