check filter permissions

def has_object_permission(self, request, view, obj):
        """
        check filter permissions
        """

        user = request.user

        if not user.is_superuser and not user.is_anonymous():
            valid = False
            try:
                ct = ContentType.objects.get_for_model(obj)
                fpm = FilterPermissionModel.objects.get(user=user,
                                                        content_type=ct)
                myq = QSerializer(base64=True).loads(fpm.filter)
                try:
                    myobj = obj.__class__.objects.filter(myq).distinct().get(pk=obj.pk)
                    if myobj:
                        valid = True
                except ObjectDoesNotExist:
                    valid = False
            except ObjectDoesNotExist:
                valid = True
            finally:
                return valid
        else:
            return True