viewsets.py

# Based on http://stackoverflow.com/a/22922156/1161156
class MultiSerializerViewSetMixin(object):
    def get_serializer_class(self):
        """
        Look for serializer class in self.serializer_action_classes, which
        should be a dict mapping action name (key) to serializer class (value),
        i.e.:

        class MyViewSet(MultiSerializerViewSetMixin, ViewSet):
            serializer_class = MyDefaultSerializer
            serializer_action_classes = {
               'list': MyListSerializer,
               'my_action': MyActionSerializer,
            }

            @action
            def my_action:
                ...

        If there's no entry for that action then just fallback to the regular
        get_serializer_class lookup: self.serializer_class, DefaultSerializer.

        """
        try:
            return self.serializer_action_classes[self.action]
        except (KeyError, AttributeError):
            return super(MultiSerializerViewSetMixin, self).get_serializer_class()


class SomeModelViewSet(MultiSerializerViewSetMixin, viewsets.ModelViewSet):
    queryset = SomeModel.objects.all()
    serializer_action_classes = {
        'list': SomeModelListSerializer,
        'create': SomeModelUpdateSerializer,
        #'retrieve': ,
        'update': SomeModelUpdateSerializer,
        'partial_update': SomeModelUpdateSerializer,
        #'destroy': ,
    }
    ...