DRF name undefined in custom serializer - django-rest-framework

Question

When I try to hit my api/atoms/ endpoint in the browser, I am getting a name undefined error in the views.py file, but it has a base name in urls.
Note: this is a non-model serializer and a ViewSet.
error
...views.py", line 74, in list
instance = atom.values(), many=True)
NameError: name 'atoms' is not defined
views.py
class AtomViewSet(viewsets.ViewSet):
serializer_class = AtomSerializer
def list(self, request):
serializer = AtomSerializer(
instance = atoms.values(), many=True) #<-------------
return Response(serializer.data)
urls.py
# for viewsets in views.py
router = DefaultRouter()
router.register(r'snippets', views.SnippetViewSet)
router.register(r'atoms', views.AtomViewSet, base_name='atoms')
urlpatterns = [
path('', views.api_root),
path('', include(router.urls)),
]
serializer.py
class AtomSerializer(serializers.Serializer):
uid = UniqueIdProperty()
created_at = DateTimeProperty()
updated_at = DateTimeProperty()
charge = IntegerProperty()
mass = FloatProperty()
def create(self, validated_data):
return Atom(id=None, **validated_data)
def update(self, instance, validated_data):
for field, value in validated_data.items():
setattr(instance, field, value)
return instance

Answer 1

This is a basic python NameError exception raised when a local or global name is not found.
The variable atoms is not defined in the list() method or globally, that's why the python interpreter raised the exception.
In your code, you'd write atoms.values(), which forces me to think that you are dealing with a QuerySet, which might be an Atom model.
class AtomViewSet(viewsets.ViewSet):
serializer_class = AtomSerializer
def list(self, request):
serializer = AtomSerializer(instance=Atom.objects.all(), many=True)
return Response(serializer.data)
Note: this is a non-model serializer and a ViewSet.
You are doing create and update operations in your AtomSerializer class, and those are directly connected to the model. I don't see any particular reason that pulls you back from using a ModelSerializer here. Apart from that, you are using the routers, which become a good choice when you deal with the CRUD operations, hence I strongly suggest you use the combination of ModelViewset and ModelSerializer in your code.

Answer 2

In your views.py you did not define atom, you need to define it first before using it or else you will get that error.
class AtomViewSet(viewsets.ViewSet):
serializer_class = AtomSerializer
def list(self, request):
# You need to define the atom first before passing it to your AtomSerializer
atoms = [] # or atom = Atom.objects.all()
serializer = AtomSerializer(
data=atoms,
many=True
)
return Response(serializer.data)