Fix Python – What is the equivalent of “none” in django templates?

I want to see if a field/variable is none within a Django template. What is the correct syntax for that?
This is what I currently have:
{% if profile.user.first_name is null %}

{% elif %}
{{ profile.user.first_name }} {{ profile.user.last_name }}
{% endif%}

In the example above, what would I use to replace “null”?
….

Fix Python – Disable a method in a ViewSet, django-rest-framework

ViewSets have automatic methods to list, retrieve, create, update, delete, …
I would like to disable some of those, and the solution I came up with is probably not a good one, since OPTIONS still states those as allowed.
Any idea on how to do this the right way?
class SampleViewSet(viewsets.ModelViewSet):
queryset = api_models.Sample.objects….