Django Mastery Quiz — Quiz

Question 1 of 10

Which form method must return `True` before you use `cleaned_data`?

aform.save()bform.clean()cform.is_valid()dform.has_changed()

Question 2 of 10

Which decorator redirects anonymous users to the login page?

a@login_requiredb@csrf_protectc@require_POSTd@never_cache

Question 3 of 10

Which generic view is designed to show a single object?

aListViewbTemplateViewcRedirectViewdDetailView

Question 4 of 10

Which default permission codename does Django create for editing a `Product` in app `shop`?

ashop.edit_productbshop.change_productcshop.update_productdshop.modify_product

Question 5 of 10

Why redirect after a successful POST instead of rendering a template?

aRedirects are fasterbTemplates cannot be rendered after POSTcIt prevents the form being resubmitted when the user refreshesdDjango requires it for CSRF

Question 6 of 10

What is wrong with this view?

class OrderCreate(CreateView, LoginRequiredMixin):
    model = Order
    fields = ['items']

aMixins cannot be used with CreateViewbLoginRequiredMixin must come before CreateView to take effectc`fields` must be a tupledCreateView requires a success_url

Question 7 of 10

Which call returns a single dictionary like `{'revenue': ...}` for the whole queryset?

aOrder.objects.aggregate(revenue=Sum('total'))bOrder.objects.annotate(revenue=Sum('total'))cOrder.objects.values('total')dOrder.objects.only('total')

Question 8 of 10

Why should `success_url` on a class-based view use `reverse_lazy`?

areverse() is deprecatedbIt caches the URL for faster redirectscIt works with POST onlydThe URLconf isn't loaded when the class attribute is evaluated at import time

Question 9 of 10

How many queries does this loop run for 50 orders (no other optimisation)?

for o in Order.objects.all():
    print(len(o.items.all()))

a1b2c51d100

Question 10 of 10

Which statement decrements stock safely even if two requests run at the same moment?

ap.stock = p.stock - 1; p.save()bProduct.objects.filter(pk=p.pk).update(stock=F('stock') - 1)cp.refresh_from_db(); p.stock -= 1; p.save()dProduct.objects.get(pk=p.pk).stock -= 1