Django Django REST Framework 3

Question 1

How does DRF's `ModelSerializer` handle the `create()` method by default?

Accepted Answer

It calls Model.objects.create() with the validated data

Answer

ModelSerializer's default create() calls Model.objects.create(**validated_data), which creates and saves the instance in one database operation.

Question 2

What does `serializer.save()` do in DRF?

Accepted Answer

Calls create() or update() depending on whether an instance was provided

Answer

If the serializer was initialized with an instance=obj argument, save() calls update(); otherwise it calls create() on the validated data.

Question 3

Which DRF pagination class splits results into pages of a fixed size?

Accepted Answer

PageNumberPagination

Answer

PageNumberPagination splits querysets into pages accessed via a page query parameter, configurable with PAGE_SIZE in DEFAULT_PAGINATION_CLASS settings.

Question 4

What is the purpose of DRF's `SerializerMethodField`?

Accepted Answer

Adds a read-only field computed by a custom method on the serializer

Answer

SerializerMethodField calls a get_<fieldname>() method on the serializer to compute the field's value, useful for derived or annotated data.

Question 5

How do you make a DRF API endpoint return XML instead of JSON?

Accepted Answer

Add XMLRenderer to the view's renderer_classes and request Accept: application/xml

Answer

DRF uses content negotiation; adding XMLRenderer to renderer_classes and sending Accept: application/xml in the request returns XML output.

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Django Practice Test

Django Django REST Framework 3