Django-rest-framework: AttributeError: 'OrderedDict' object has no attribute 'pk'

Created on 24 May 2015 · 4Comments · Source: encode/django-rest-framework

views:

@detail_route(methods=['post'])
def quote(self, request, pk):
    task = self.get_object()

    serializer = serializers.TaskCreateQuoteSerializer(data=request.DATA, task=task)

    if not serializer.is_valid():
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

    # this causes a problem
    serializer.data['servicetasks']:

serializers:

class TaskCreateQuoteSerializer(serializers.Serializer):
    servicetasks = serializers.PrimaryKeyRelatedField(many=True, required=True, allow_null=False,
        queryset=ServiceTask.objects.all())

    def __init__(self, task, *args, **kwargs):
        super(TaskCreateQuoteSerializer, self).__init__(*args, **kwargs)
        # print task.servicetask_set.all()
        # self.fields['servicetasks'].queryset = task.servicetask_set.all()

When I try and print the serializer:

TaskCreateQuoteSerializer(data={u'servicetasks': [3115, 3114]}, task=<Task: E13/688 COMPLETE>):
    servicetasks = PrimaryKeyRelatedField(allow_null=False, many=True, queryset=[<ServiceTask: Ser...]

So whenever I try and access serializer.data I get an exception:

AttributeError: 'OrderedDict' object has no attribute 'pk'

Traceback:
File "/usr/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  111.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/usr/local/lib/python2.7/site-packages/django/views/decorators/csrf.py" in wrapped_view
  57.         return view_func(*args, **kwargs)
File "/usr/local/lib/python2.7/site-packages/rest_framework/viewsets.py" in view
  85.             return self.dispatch(request, *args, **kwargs)
File "/usr/local/lib/python2.7/site-packages/rest_framework/views.py" in dispatch
  452.             response = self.handle_exception(exc)
File "/usr/local/lib/python2.7/site-packages/rest_framework/views.py" in dispatch
  449.             response = handler(request, *args, **kwargs)
File "/usr/src/app/abas/apps/api/views.py" in quote
  270.         if not serializer.data['servicetasks']:
File "/usr/local/lib/python2.7/site-packages/rest_framework/serializers.py" in data
  466.         ret = super(Serializer, self).data
File "/usr/local/lib/python2.7/site-packages/rest_framework/serializers.py" in data
  215.                 self._data = self.to_representation(self.validated_data)
File "/usr/local/lib/python2.7/site-packages/rest_framework/serializers.py" in to_representation
  426.                 attribute = field.get_attribute(instance)
File "/usr/local/lib/python2.7/site-packages/rest_framework/relations.py" in get_attribute
  364.         if not instance.pk:

Source

aidanlister

Most helpful comment

The serializer.data property is only valid if you have a saved instance to serializer.
Either call serializer.save() or use serializer.validated_data to access data prior to saving.
We should consider an explicit guard against this usage.

tomchristie on 26 May 2015

👍9

All 4 comments

tomchristie on 26 May 2015

👍9

I encountered this as well using the detail_route decorator for a similar purpose. Took a long time to figure out what was going on. It would be helpful if there was a guard against this that stated your previous response of The serializer.data property is only valid if you have a saved instance to serializer. Either call serializer.save() or use serializer.validated_data to access date prior to saving.

thenewguy on 8 Sep 2015

👍1

@tomchristie The current error here is while accessing the data so we can't say "Either call serializer.save() or use serializer.validated_data to access date prior to saving." since the later doesn't work anyway in that case.

Edited.