test de videos que le dieron clic los papás...

api_test.py

# en la api genero el action
class ParentSchoolViewSet(
        GenericViewSet,
        mixins.RetrieveModelMixin,
        mixins.ListModelMixin,
        mixins.CreateModelMixin,
        mixins.PartialUpdateModelMixin,
        mixins.DestroyModelMixin):

    serializer_class = serializers.ParentSchoolSerializer
    retrieve_serializer_class = serializers.ParentSchoolSerializer
    list_serializer_class = serializers.ParentSchoolSerializer
    update_serializer_class = serializers.ParentSchoolCreateSerializer
    create_serializer_class = serializers.ParentSchoolCreateSerializer
    change_image_serializer_class = serializers.ParentSchoolImageSerializer

    permission_classes = [
        C(TutorReadPermission) |
        C(AdminPermission)
    ]

    parent_model = ParentSchool
    parent_model_name = 'ParentSchool'
    parent_lookup_field = 'parentschool_pk'

    def get_queryset(self, *args, **kwargs):
        queryset = ParentSchool.objects.all()

        if self.request.user.has_tutor_permissions:
            queryset = queryset.filter(is_active=True)

        return queryset.order_by('-created_date')

    def retrieve(self, request, *args, **kwargs):
        """
        Returns an specific parent school resource.
        ---
        response_serializer: serializers.ParentSchoolSerializer

        responseMessages:
            - code: 200
              message: OK
            - code: 403
              message: FORBIDDEN
            - code: 404
              message: NOT FOUND
            - code: 500
              message: INTERNAL SERVER ERROR
        consumes:
            - application/json
        produces:
            - application/json
        """
        #
        # Record a open video from parent_school
        #
        parentschool = ParentSchool.objects.get(pk=kwargs['parentschool_pk'])

        origin_queryparam = request.query_params.get('origin', 'app')
        action_list = Action.objects.list_action(origin_queryparam)
        action.send(
            request.user,
            verb=settings.CUSTOM_APP_ACTIONS['parents_school'],
            description=(u'Clic en video {}'.format(parentschool.title)),
            action_object=action_list,
            target=parentschool
        )

        return super(ParentSchoolViewSet, self).retrieve(request, args, kwargs)
      
#-------------------------------------------------
# esto en los test
# -*- coding: utf-8 -*-
from django.core.management import call_command
from django.core.urlresolvers import reverse

from rest_framework import status
from rest_framework.test import APITestCase

from potencia.core.api.tests import tests_viewsets


class AppParentsActivitiesTests(APITestCase, tests_viewsets.ApiTestMixin):

    def setUp(self):
        call_command('loaddata', 'roles.json', verbosity=0)
        call_command('loaddata', 'actions.json', verbosity=0)
        call_command('loaddata', 'parent_school_resources.json', verbosity=0)

    def test_parent_school_open_video(self):
        endpoint_url = reverse(
                            'api:v1:parent-schools-retrieve',
                            args=(1,)
                        )

        token = self.create_tutor_token()[1]
        response = self.client.post(
            endpoint_url, HTTP_AUTHORIZATION=token, format='json'
        )
        self.assertEqual(response.status_code, status.HTTP_200_OK)

Tu endpoint url esta mal, debe ser algo así:

endpoint_url = reverse(
    'api:v1:parent-schools-detail',
     kwargs={'parentschool_pk: <parentschool_id>}
)