Attempting to start the server and getting error line like

```
NoReverseMatch at /polls/
Reverse for 'detail' with arguments '(1,)' not found. 1 pattern(s) tried: ['polls/<int:pk>/']

```

my views.py

```
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'

```

Views for index,results and detail

my urls.py

```
from django.conf.urls import url

from . import views

app_name = 'polls'

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

```

my index.html

```
{% if latest_question_list %}
    <ul>
    {% for question in latest_question_list %}
        <li><a href="{% url 'polls:detail' question.id %}">{{ question.question_text }}</a></li>
    {% endfor %}
    </ul>
{% else %}
    <p>No polls are available.</p>
{% endif %}

```

I have tried many time but i didn't got a solution please help me out.