ViewSets and routers in Django - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this ViewSet router URL pattern?

Given the following Django REST Framework router and ViewSet, what URL pattern will be registered for the 'list' action?

Django

from rest_framework import routers, viewsets
from django.urls import path, include

class BookViewSet(viewsets.ViewSet):
    def list(self, request):
        pass

router = routers.DefaultRouter()
router.register(r'books', BookViewSet, basename='book')

urlpatterns = [
    path('', include(router.urls)),
]

A /book/list/ mapped to BookViewSet list action

B /book/ mapped to BookViewSet list action

C /books/ mapped to BookViewSet list action

D /books/list/ mapped to BookViewSet list action

💡 Hint

Remember how DefaultRouter registers routes for ViewSets using the basename and prefix.

The DefaultRouter registers the 'list' action at the prefix path, so 'books/' is the correct URL for the list action.

❓ state_output

intermediate

What is the HTTP method for the 'create' action in a ViewSet?

In Django REST Framework, which HTTP method triggers the 'create' action in a ViewSet when using a router?

A GET

B POST

C PUT

D DELETE

💡 Hint

Think about which HTTP method is used to add new data.

The 'create' action corresponds to the POST HTTP method to add new resources.

📝 Syntax

advanced

Which option correctly registers a ViewSet with a router for nested routes?

You want to register a nested route for comments under posts using routers in Django REST Framework. Which code snippet correctly does this?

A

router.register(r'posts', PostViewSet)
nested_router = routers.NestedDefaultRouter(router, r'posts', lookup='post')
nested_router.register(r'comments', CommentViewSet, basename='post-comments')

B router.register(r'posts/(?P<post_pk>[^/.]+)/comments', CommentViewSet, basename='post-comments')

C

router.register(r'posts', PostViewSet)
router.register(r'posts/comments', CommentViewSet)

D

router.register(r'posts', PostViewSet)
router.register(r'comments', CommentViewSet)

💡 Hint

Nested routes require a special nested router, not just string patterns.

Option A uses NestedDefaultRouter to properly create nested routes with lookup fields.

🔧 Debug

advanced

Why does this ViewSet raise a 405 Method Not Allowed error?

Consider this ViewSet: class ArticleViewSet(viewsets.ViewSet): def retrieve(self, request, pk=None): return Response({'id': pk}) router.register(r'articles', ArticleViewSet) Why does a GET request to /articles/ return 405 Method Not Allowed?

A Because the basename is missing in router.register

B Because 'retrieve' method is missing the 'self' parameter

C Because the router is not included in urlpatterns

D Because 'list' method is not defined, so GET on /articles/ is not allowed

💡 Hint

Check which actions correspond to which URLs and HTTP methods.

GET on /articles/ calls the 'list' action, which is not defined, so 405 is returned.

🧠 Conceptual

expert

What is the main advantage of using routers with ViewSets in Django REST Framework?

Why do developers prefer using routers with ViewSets instead of manually defining URL patterns for each view?

A Routers automatically generate standard RESTful URL patterns and reduce repetitive code

B Routers improve database query performance by caching queries

C Routers allow using class-based views without serializers

D Routers enable asynchronous request handling by default

💡 Hint

Think about how routers help with URL management and code simplicity.

Routers simplify URL routing by automatically creating RESTful routes for ViewSets, reducing manual URL definitions.