Django エラー内容が分からない

Question

前提・実現したいこと

Djangoにおいて発生したエラーを解消したい
該当する箇所がどこなのか分からず困ってます
どなたかご教授頂けると幸いです
http://127.0.0.1:8000/polls/でエラーが発生

発生している問題・エラーメッセージ

NoReverseMatch at /polls/
Reverse for 'detail' with arguments '('',)' not found. 1 pattern(s) tried: ['polls/(?P<pk>[0-9]+)/$']
Request Method:	GET
Request URL:	http://127.0.0.1:8000/polls/
Django Version:	3.0.1
Exception Type:	NoReverseMatch
Exception Value:	
Reverse for 'detail' with arguments '('',)' not found. 1 pattern(s) tried: ['polls/(?P<pk>[0-9]+)/$']
Exception Location:	C:\Users\sa96t\AppData\Local\Programs\Python\Python38-32\lib\site-packages\django\urls\resolvers.py in _reverse_with_prefix, line 677
Python Executable:	C:\Users\sa96t\AppData\Local\Programs\Python\Python38-32\python.exe
Python Version:	3.8.0
Python Path:	
['C:\Users\sa96t\Desktop\Django\mysite',
 'C:\Users\sa96t\AppData\Local\Programs\Python\Python38-32\python38.zip',
 'C:\Users\sa96t\AppData\Local\Programs\Python\Python38-32\DLLs',
 'C:\Users\sa96t\AppData\Local\Programs\Python\Python38-32\lib',
 'C:\Users\sa96t\AppData\Local\Programs\Python\Python38-32',
 'C:\Users\sa96t\AppData\Local\Programs\Python\Python38-32\lib\site-packages']
Server time:	Sun, 12 Jan 2020 01:19:50 +0000
Error during template rendering
In template C:\Users\sa96t\Desktop\Django\mysite\polls\templates\polls\index.html, error at line 8

Reverse for 'detail' with arguments '('',)' not found. 1 pattern(s) tried: ['polls/(?P<pk>[0-9]+)/$']
1	{% load static %}
2	
3	<link rel="stylesheet" type="text/css" href="{% static 'polls/style.css' %}">
4	
5	{% if latest_question_list %}
6	    <ul>
7	        {% for question in latest_question_list %}
8	            <li><a href="{% url 'polls:detail' question_id %}">{{ question.question_text }}</a></li>
9	        {% endfor %}
10	    </ul>
11	{% else %}
12	    <p>No polls are available</p>
13	{% endif %}

該当のソースコード

{% load static %}

<link rel="stylesheet" type="text/css" href="{% static 'polls/style.css' %}">

{% 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 %}

from django.urls import path

from . import views

app_name = 'polls'

urlpatterns = [
    #path('', views.index, name='index'),
    #path('<int:question_id>/', views.detail, name='detail'),
    #path('<int:question_id>/result', views.results, name='result'),
    path('<int:question_id>/vote/', views.vote, name='vote'),
    
    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'),
]

from django.shortcuts import render

from django.http import HttpResponse
from .models import Question
from django.template import loader
from django.http import Http404

from django.http import HttpResponse, HttpResponseRedirect
from django.shortcuts import get_object_or_404, render
from django.urls import reverse
from .models import Choice, Question

from django.views import generic
from django.utils import timezone

# Create your views here.
'''
def index(request):
    latest_question_list = Question.object.order_bey('-pub_date')[:5]
    #output = ', '.join([q.question_text for q in latest_question_list])
    #return HttpResponse(output)
    
    #template = loader.get_template('polls/index.html')
    context = {
       'latest_question_list': latest_question_list,
    }
    #return HttpResponse(template.render(context, request))

    return render(request, 'polls/index.html', context)

def detail(request, question_id):
    #return HttpResponse("You're looking at question %s." % question_id)

    #try:
    #    question = Question.objects.get(pk=question_id)
    #except Question.DoesNotExist:
    #    raise Http404("Question doesn't exist")
    
    question = get_object_or_404(Question, pk=question_id)

    #return render(request, 'polls/detail.html', {'question': question}) 

    try:
        selected_choice = question.choice_set.get(pk=request.POST['choice'])
    except(KeyError, Choice.DoesNotExist):
        return render(request, 'polls/detail.html', {
            'question': question,
            'error_message': "You didn't select a choice",
        })
    else:
        selected_choice.votes += 1
        selected_choice.save()
        return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))

def results(request, question_id):
    #response = "You're looking at the results of questoin %s."
    #return HttpResponse(response % question_id)

    question = get_object_or_404(Question, pk=question_id)
    return render(request, 'polls/results.html', {'question': question})
'''

def vote(request, question_id):
    return HttpResponse("You're voting on question %s." % question_id)

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

    def get_queryset(self):
        #return Question.objects.order_by('-pub_date')[:5]

        return Question.objects.filter(
            pub_date__lte = timezone.now()
        ).order_by('-pub_date')[:5]

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

    def get_queryset(self):
        return Question.objects.filter(pub_date__lte=timezone.now())

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

試したこと

エラー内容と以下のサイトを参照して、
polls/templates/polls/index.htmlもしくはpolls/urls.pyのタイポだと思った
参照サイト

補足情報

以下のサイトを初めから実践しており、その6まで
参考情報

Answer 1

<li><a href="{% url 'polls:detail' pk=question_id %}">{{ question.question_text }}</a></li>

Comments

[退会済みユーザー]

回答の程、ありがとうございます。
該当箇所を書き換えてみましたが、同じようなエラーが発生してしまいます。

[harinezumi.py]

こちらはどうでしょうか
<li><a href="{% url 'polls:detail' question.id %}">{{ question.question_text }}</a></li>

[退会済みユーザー]

回答の程、ありがとうございます。
上手くいきました。
本当にありがとうございました。

[harinezumi.py]

良かったです、回答の評価いただけたら幸いです。

[harinezumi.py]

もし大丈夫であれば、解決済をしてください