python - 'collections.OrderedDict' 对象没有属性 'pk' - django rest 框架

Question

我有一个模型，我想写一个 update()方法来更新。
下面的代码片段是我的模型:

class Klass(models.Model):
    title = models.CharField(max_length=50)
    description = models.CharField(max_length=500)
    university = models.CharField(max_length=50,blank=True, null=True)
    teacher = models.ForeignKey(Profile, related_name='teacher', on_delete=models.CASCADE)

下面的代码片段是对应的 Serializer :

class KlassSerializer(ModelSerializer):
        teacher = ProfileSerializer()
        url = HyperlinkedIdentityField(view_name='mainp-api:detail', lookup_field='pk')
        klass_settings = KlassSettingsSerializer()

    class Meta:
        model = Klass
        fields = ('url', 'id', 'title', 'description', 'university','teacher')

    
    def update(self, instance, validated_data):
        instance.title = validated_data.get('title', instance.title)
        instance.description = validated_data.get('description', instance.description)
        instance.university = validated_data.get('university', instance.university)
        instance.save()

        return instance

对于更新，我使用以下代码段:

class KlassAPIView(APIView):    
    def put(self, request, pk=None):
        if pk == None:
            return Response({'message': 'You must specify class ID'}, status=HTTP_400_BAD_REQUEST)

        klass = Klass.objects.get(pk=pk)
        if request.user.profile.type != 't':
            raise PermissionDenied(detail={'message': 'You aren't teacher of this class, so you can't edit information.'})

        serializer = KlassSerializer(data=request.data, context={'request': request})
        serializer.initial_data['teacher'] = request.user.profile.__dict__

        if serializer.is_valid():
            serializer.update(instance=klass, validated_data=serializer.data)  # Retrieve teacher and store
            return Response({'data': serializer.data}, status=HTTP_200_OK)
        else:
            return Response({'data': serializer.errors}, status=HTTP_400_BAD_REQUEST)

但是当我用 PUT 发送数据时方法，它返回以下错误:

AttributeError at /api/class/49/

'collections.OrderedDict' object has no attribute 'pk'

并且错误发生在 serializer.update(instance=klass, validated_data=serializer.data)线。

Answer 1

刚刚遇到了同样的错误。
就我而言，问题是我访问了 serializer.data做之前serializer.save() .
谷歌把我放在这里，所以也许其他人也会觉得这很有帮助。
来源:https://github.com/encode/django-rest-framework/issues/2964