TypeError: Object of type 'User' is not JSON serializable. Why is this happening?

Question

I'm trying to create a new user using DRF. The code actually creates the user but I get a 500 error saying that user is not JSON serializable. I would like to get rid of this error. Here are how my files look

views.py

class UserCreateAPIView(ModelViewSet):
    queryset = EndUser.objects.all()
    serializer_class = NewUserSerializer
    permission_classes = (AllowAny,)

serializers.py

class NewUserSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.EndUser
        fields = ('id', 'first_name', 'last_name', 'email', 'title', 'user_type', 'packages', 'practice_area',
                  'office_phone', 'level', 'companies', 'country', 'password', 'firm', 'sectors', 'verticals', 'user_ptr')

    def save(self, *args, **kwargs):
        user = super().save(*args, **kwargs)
        user.set_password(user.password)
        user.save()

urls.py

router.register('new-user', views.UserCreateAPIView)

Enduser inherits User. Would anyone have any ideas on how to fix this?

Answer 1

You should remove the user_ptr field which is, If I understood it correctly the OneToOneField Django constructed for its model inheritance:

class NewUserSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.EndUser
        fields = ('id', 'first_name', 'last_name', 'email', 'title'
          , 'user_type', 'packages', 'practice_area'
          , 'office_phone', 'level', 'companies', 'country'
          , 'firm', 'sectors', 'verticals', 'password'
        )  # no  user_ptr
        extra_kwargs = {'password': {'write_only': True}}

    def save(self, *args, **kwargs):
        user = super().save(*args, **kwargs)
        user.set_password(user.password)
        user.save()

While Django will hash passwords, it is not a good idea to mark the password as a field that can be read. It means that you will retrieve the password hash, and although that might still require a lot of computational effort to obtain the real password, it is still not a good idea.