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If you face an error like below, you should check if your python is properly installed and django is running on virtual environment like I mentioned at "1.1. How do I setup Django development environment on Mac?" or not.

STEP 3. Database setup

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Convert the URLconf.

Code Block

language	py
title	polls/urls.py

from django.urls import path

from . import views

app_name = 'polls'
urlpatterns = [
    path('', views.IndexView.as_view(), name='index'),
    path('<int:pk>/', views.DetailView.as_view(), name='detail'),
    path('<int:pk>/results/', views.ResultsView.as_view(), name='results'),
    path('<int:question_id>/vote/', views.vote, name='vote'),
]

Delete some of the old, unneeded views.
Next, we’re going to remove our old index, detail, and results views and use Django’s generic views instead. To do so, open the polls/views.py file and change it like so:

Code Block

language	py
title	polls/view.py

from django.http import HttpResponseRedirect
from django.shortcuts import get_object_or_404, render
from django.urls import reverse
from django.views import generic

from .models import Choice, Question


class IndexView(generic.ListView):
    template_name = 'polls/index.html'
    context_object_name = 'latest_question_list'

    def get_queryset(self):
        """Return the last five published questions."""
        return Question.objects.order_by('-pub_date')[:5]


class DetailView(generic.DetailView):
    model = Question
    template_name = 'polls/detail.html'


class ResultsView(generic.DetailView):
    model = Question
    template_name = 'polls/results.html'


def vote(request, question_id):
    ... # same as above, no changes needed.

Introduce new views based on Django’s generic views.
We’re

From above, we’re using two generic views here: ListView and DetailView. Respectively, those two views abstract the concepts of “display a list of objects” and “display a detail page for a particular type of object.”

(1) Each generic view needs to know what model it will be acting upon. This is provided using the model attribute.
(2) The DetailView generic view expects the primary key value captured from the URL to be called "pk", so we’ve changed question_id to pk for the generic views.

By default, the DetailView generic view uses a template called <app name>/<model name>_detail.html. In our case, it would use the template "polls/question_detail.html". The template_name attribute is used to tell Django to use a specific template name instead of the autogenerated default template name. We also specify the template_name for the results list view – this ensures that the results view and the detail view have a different appearance when rendered, even though they’re both a DetailView behind the scenes.

Similarly, the ListView generic view uses a default template called <app name>/<model name>_list.html; we use template_name to tell ListView to use our existing "polls/index.html" template.

In previous parts of the tutorial, the templates have been provided with a context that contains the question and latest_question_list context variables. For DetailView the question variable is provided automatically – since we’re using a Django model (Question), Django is able to determine an appropriate name for the context variable. However, for ListView, the automatically generated context variable is question_list. To override this we provide the context_object_name attribute, specifying that we want to use latest_question_list instead. As an alternative approach, you could change your templates to match the new default context variables – but it’s a lot easier to just tell Django to use the variable you want.

Run the server, and use your new polling app based on generic views.

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STEP 3. Database setup