Why advanced DRF features matter in Django - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the main DRF class for creating API views.

Django

from rest_framework.views import [1]

Drag options to blanks, or click blank then click option'

AModelView

BSerializer

CAPIView

DViewSet

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'ViewSet' instead of 'APIView' for basic API views.

Confusing 'Serializer' with view classes.

The APIView class is the base class for creating API views in DRF.

2fill in blank

medium

Complete the code to add pagination to a DRF view.

Django

from rest_framework.pagination import [1]

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ALimitOffsetPagination

BCursorPagination

CBasicPagination

DPageNumberPagination

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 'BasicPagination' which does not exist.

Confusing 'LimitOffsetPagination' with page number style.

PageNumberPagination is a common pagination class that divides results into pages.

3fill in blank

hard

Fix the error in the serializer by completing the field declaration.

Django

class UserSerializer(serializers.Serializer):
    email = serializers.[1](max_length=100)

Drag options to blanks, or click blank then click option'

AEmailField

BIntegerField

CCharField

DDateField

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'CharField' which does not validate email format.

Using unrelated field types like 'IntegerField'.

EmailField validates that the input is a valid email address.

4fill in blank

hard

Fill both blanks to create a viewset with a custom queryset and serializer.

Django

class ProductViewSet(viewsets.[1]):
    queryset = Product.objects.[2]()

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AModelViewSet

BReadOnlyModelViewSet

CGenericViewSet

DViewSet

Eall

Ffilter

Gget

Hexclude

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'ReadOnlyModelViewSet' when write operations are needed.

Using 'filter()' without parameters which causes errors.

ModelViewSet provides full CRUD operations, and all() returns all products.

5fill in blank

hard

Fill all three blanks to define a serializer with a nested serializer and a custom validation method.

Django

class AddressSerializer(serializers.Serializer):
    street = serializers.CharField(max_length=100)

class UserSerializer(serializers.Serializer):
    name = serializers.CharField(max_length=50)
    address = [1]()

    def validate_name(self, value):
        if len(value) < [2]:
            raise serializers.ValidationError("Name too short")
        return value

    def validate(self, data):
        if data['name'] == 'admin' and data['address']['street'] == [3]:
            raise serializers.ValidationError("Admin cannot live on this street")
        return data

Drag options to blanks, or click blank then click option'

ANestedSerializer

BCharField

C5

DAddressSerializer

EIntegerField

F10

G"Forbidden Street"

H"Main Street"

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'CharField' for the nested address instead of a serializer field.

Setting the minimum length too high or too low.

Using the wrong street name in validation.

AddressSerializer() defines a nested serializer for the address field. The minimum name length is 5, and admin users cannot live on "Forbidden Street".

Practice

1. Why is it important to use advanced features like permissions in Django REST Framework (DRF)?

easy

A. To control who can access or modify API data

B. To speed up the server hardware

C. To change the database schema automatically

D. To make the API look prettier on the frontend

Solution

1. Step 1: Understand the role of permissions in DRF

   Permissions restrict or allow access to API endpoints based on user roles or authentication.

2. Step 2: Identify the purpose of permissions

   Permissions help keep data safe by controlling who can read or change it.

3. Final Answer:

   To control who can access or modify API data -> Option A

4. Quick Check:

   Permissions = Control access [OK]

Hint: Permissions control access rights in APIs [OK]

Common Mistakes:

• Thinking permissions improve server speed
• Confusing permissions with database changes
• Assuming permissions affect frontend design

2. Which of the following is the correct way to add pagination in a DRF viewset?

easy

A. pagination_class = PageNumberPagination

B. paginate = True

C. pagination = 'enabled'

D. page_size = 10

Solution

1. Step 1: Recall DRF pagination syntax

   DRF uses the attribute pagination_class to set pagination behavior in viewsets.

2. Step 2: Match the correct attribute and value

   Assigning PageNumberPagination to pagination_class enables page-based pagination.

3. Final Answer:

   pagination_class = PageNumberPagination -> Option A

4. Quick Check:

   Pagination uses pagination_class = PageNumberPagination [OK]

Hint: Use pagination_class to enable pagination in DRF [OK]

Common Mistakes:

• Using incorrect attribute names like paginate or pagination
• Setting page_size without pagination_class
• Assigning string values instead of classes

3. Given this DRF serializer method:

class MySerializer(serializers.ModelSerializer):
    def create(self, validated_data):
        user = self.context['request'].user
        validated_data['owner'] = user
        return super().create(validated_data)

What does this method do when creating an object?

medium

A. It raises an error because 'owner' is not in validated_data

B. It ignores the user and creates an anonymous object

C. It assigns the current user as the owner of the new object

D. It deletes the user from the request context

Solution

1. Step 1: Analyze the create method override

   The method adds the current user from the request context to the validated data under 'owner'.

2. Step 2: Understand the effect on object creation

   By adding 'owner', the created object will link to the user who made the request.

3. Final Answer:

   It assigns the current user as the owner of the new object -> Option C

4. Quick Check:

   create() adds user as owner [OK]

Hint: create() can add user info from context automatically [OK]

Common Mistakes:

• Assuming it raises error if 'owner' missing
• Thinking it deletes user from context
• Believing it ignores user data

4. You have this DRF viewset snippet:

class MyViewSet(viewsets.ModelViewSet):
    queryset = MyModel.objects.all()
    serializer_class = MySerializer
    permission_classes = [IsAuthenticated]

    def get_queryset(self):
        return MyModel.objects.filter(owner=self.request.user)

What is the main issue with this code?

medium

A. serializer_class must be a list, not a single class

B. permission_classes should be a tuple, not a list

C. get_queryset should not filter by owner

D. The queryset attribute is overridden by get_queryset, so it is redundant

Solution

1. Step 1: Understand get_queryset overriding

   Defining get_queryset replaces the queryset attribute for filtering dynamically.

2. Step 2: Identify redundancy

   Since get_queryset returns a filtered queryset, the class-level queryset is not used and is redundant.

3. Final Answer:

   The queryset attribute is overridden by get_queryset, so it is redundant -> Option D

4. Quick Check:

   get_queryset overrides queryset attribute [OK]

Hint: get_queryset overrides queryset attribute in viewsets [OK]

Common Mistakes:

• Thinking permission_classes must be a tuple
• Believing filtering by owner is wrong here
• Assuming serializer_class must be a list

5. You want to create a DRF API that returns a paginated list of items owned by the logged-in user, and automatically assigns the user as owner when creating new items. Which combination of features should you use?

hard

A. Use pagination_class only, without filtering or permissions

B. Use permission_classes to require login, override get_queryset to filter by user, use pagination_class, and override serializer create() to set owner

C. Use permission_classes to allow all, override get_queryset to return all items, and do not override create()

D. Use no permissions, set queryset to all items, disable pagination, and set owner manually in frontend

Solution

1. Step 1: Identify security and filtering needs

   Require login with permission_classes and filter queryset by logged-in user to show only their items.

2. Step 2: Add pagination and automatic owner assignment

   Use pagination_class to handle large data sets and override serializer create() to assign owner automatically.

3. Final Answer:

   Use permission_classes to require login, override get_queryset to filter by user, use pagination_class, and override serializer create() to set owner -> Option B

4. Quick Check:

   Permissions + filtering + pagination + create() override = D [OK]

Hint: Combine permissions, filtering, pagination, and create() override [OK]

Common Mistakes:

• Ignoring permissions and filtering
• Not using pagination for large data
• Setting owner only on frontend