Filtering using viewsets in django rest framework

Register your route as

router.register(r'date-list', views.DateListViewSet)

now change your viewset as shown below,

class DateListViewSet(viewsets.ModelViewSet):
    queryset = TimeTable.objects.all()
    serializer_class = TimeTableSerializer
    lookup_field = 'movie_id'

    def retrieve(self, request, *args, **kwargs):
        movie_id = kwargs.get('movie_id', None)
        movie = Movie.objects.get(id=movie_id)
        self.queryset = TimeTable.objects.filter(show__movie=movie).distinct()
        return super(DateListViewSet, self).retrieve(request, *args, **kwargs)

Use a retrieve method, which will match any GET requests to endpoint /date-list/<id>/.

Advantage is that you don't have to explicitly handle the serialization and returning response you make ViewSet to do that hard part. We are only updating the queryset to be serialized and rest framework does the rest.

Since ModelViewSet is implemented as,

class ModelViewSet(mixins.CreateModelMixin,
                   mixins.RetrieveModelMixin,
                   mixins.UpdateModelMixin,
                   mixins.DestroyModelMixin,
                   mixins.ListModelMixin,
                   GenericViewSet):
    """
    A viewset that provides default `create()`, `retrieve()`, `update()`,
    `partial_update()`, `destroy()` and `list()` actions.
    """
    pass

Its implementation includes the following methods (HTTP verb and endpoint on bracket)

• list() (GET /date-list/)
• create()(POST /date-list/)
• retrieve()(GET date-list/<id>/)
• update() (PUT /date-list/<id>/)
• partial_update() (PATCH, /date-list/<id>/
• destroy() (DELETE /date-list/<id>/)

If you want only to implement the retrieve() (GET requests to endpoint date-list/<id>/), you can do this instead of a `ModelViewSet),

from rest_framework import mixins, views

class DateListViewSet(mixins.RetrieveModelMixin, viewsets.GenericViewSet):
    queryset = TimeTable.objects.all()
    serializer_class = TimeTableSerializer
    lookup_field = 'movie_id'

    def retrieve(self, request, *args, **kwargs):
        movie_id = kwargs.get('movie_id', None)
        movie = Movie.objects.get(id=movie_id)
        self.queryset = TimeTable.objects.filter(show__movie=movie).distinct()
        return super(DateListViewSet, self).retrieve(request, *args, **kwargs)

ModelViewSet by design assumes that you want to implement a CRUD(create, update, delete)
There is also a ReadOnlyModelViewSet which implements only the GET method to read only endpoints.
For Movie and Show models, a ModelViewSet or ReadOnlyModelViewSet is a good choice whether you want implement CRUD or not.
But a separate ViewSet for a related query of a TimeTable which describes a Movie model's schedule doesn't looks so good.
A better approach would be to put that endpoint to a MovieViewSet directly. DRF provided it by @detail_route and @list_route decorators.

from rest_framework.response import Response
from rest_framework.decorators import detail_route

class MovieViewSet(viewsets.ModelViewset):

    queryset = Movie.objects.all()
    serializer_class = MovieSerializer

    @detail_route()
    def date_list(self, request, pk=None):
        movie = self.get_object() # retrieve an object by pk provided
        schedule = TimeTable.objects.filter(show__movie=movie).distinct()
        schedule_json = TimeTableSerializer(schedule, many=True)
        return Response(schedule_json.data)

This endpoint will be available by a movie-list/:id/date_list url
Docs about extra routes