[FIXED] Django / Django Rest Framework ModelViewSet: __init__() takes 1 positional argument but 2 were given

Issue

I'm trying to create a custom "list" under OptionViewSet but It's giving me an error.

class OptionViewSet(viewsets.ModelViewSet):
    serializer_class = OptionSerializer
    queryset = Option.objects.all()

    def list(self, request):
        queryset = Option.objects.all()
        serializer = OptionSerializer(queryset, many=True)
        return Response(serializer.data)

Error

__init__() takes 1 positional argument but 2 were given

This works fine:

class OptionViewSet(viewsets.ModelViewSet):
    serializer_class = OptionSerializer
    queryset = Option.objects.all()

urls.py

path('api/shipping/', include((shipping_routes.urls, 'shipping'), namespace='shipping')),

routes.py

routes.register(r'option', OptionViewSet, basename='option')

serializer

class OptionSerializer(serializers.ModelSerializer):
    class Meta:
        model = Option
        fields = ['id', 'extra', 'name']

full traceback

Traceback (most recent call last):
  File "C:\Users\Simon\.virtualenvs\django_backend-ZmgaAA1F\lib\site-packages\django\core\handlers\exception.py", line 47, in inner
    response = get_response(request)
  File "C:\Users\Simon\.virtualenvs\django_backend-ZmgaAA1F\lib\site-packages\django\core\handlers\base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "C:\Users\Simon\.virtualenvs\django_backend-ZmgaAA1F\lib\site-packages\django\views\decorators\csrf.py", line 54, in wrapped_view
    return view_func(*args, **kwargs)
  File "C:\Users\Simon\.virtualenvs\django_backend-ZmgaAA1F\lib\site-packages\rest_framework\viewsets.py", line 125, in view
    return self.dispatch(request, *args, **kwargs)
  File "C:\Users\Simon\.virtualenvs\django_backend-ZmgaAA1F\lib\site-packages\rest_framework\views.py", line 509, in dispatch
    response = self.handle_exception(exc)
  File "C:\Users\Simon\.virtualenvs\django_backend-ZmgaAA1F\lib\site-packages\rest_framework\views.py", line 469, in handle_exception
    self.raise_uncaught_exception(exc)
  File "C:\Users\Simon\.virtualenvs\django_backend-ZmgaAA1F\lib\site-packages\rest_framework\views.py", line 480, in raise_uncaught_exception
    raise exc
  File "C:\Users\Simon\.virtualenvs\django_backend-ZmgaAA1F\lib\site-packages\rest_framework\views.py", line 506, in dispatch
    response = handler(request, *args, **kwargs)
  File "C:\Users\Simon\Documents\GitHub\crud-react-django\django_backend\shipping\views.py", line 18, in list
    return Response(serializer.data)

Exception Type: TypeError at /api/shipping/option/
Exception Value: __init__() takes 1 positional argument but 2 were given

Solution

I had the wrong Response import. Imported it from "requests" instead of "rest_framework.response".

Answered By - SJ19