NoReverseMatch at/ something wrong with url with slug

Question

我得到 NoReverseMatch at /:

Reverse for 'category' with arguments '(u'',)' and keyword arguments '{}' not found. 1 pattern(s) tried: ['category/(?P[\w\-]+)/$']

我不确定哪里出了问题。我知道它是在哪里造成的，但我不知道为什么。此 url 导致错误：

url(r'^category/(?P<category_name_slug>[\w\-]+)/$', views.category, name='category'),

错误来自此 index.html

{% for category in categories %}
    <li class="list-group-item"><a href="{% url 'category' category.slug %}">{{ category.name }}</a></li>
{% endfor %}

我很确定我的 views.py 没有问题，但以防万一我会 post 在这里

    #for front page

def index(request):
        """This view return index page. In index page, there is thread list.
        And thread list can be sorted by score, number of comment, date, title using paging.
        GET parameters are 'sort' and 'page'. 'sort' is sorting methods. 'page' is number of page.
        :param request: Django request object
        :return: Thread list page
        """

        categories = Category.objects.all()

        try:
                sort = request.GET["sort"].strip()
                sort_method = SortMethods[sort]
                page = request.GET["page"].strip()
        except KeyError:
                sort_method = SortMethods.score
                page = 1

        if sort_method == SortMethods.date:
                thread_list = Post.objects.order_by("-pub_date")
        else:
                thread_list = Post.objects.all()
                thread_list = sorted(thread_list, key=lambda x: x.get_score(), reverse=True)

        paginator = Paginator(thread_list, 30)

        try:
                posts = paginator.page(page)
        except PageNotAnInteger:
                posts = paginator.page(1)
        except EmptyPage:
                posts = paginator.page(paginator.num_pages)

        context = {
                "posts": posts,
                "pages": paginator.page_range,
                "sort": sort_method.name,
                "categories":categories
        }
        return render(request, "main/index.html", context)

#for single-post page
def post(request, slug):
        single_post = get_object_or_404(Post, slug=slug)
        single_post.views += 1  # increment the number of views
        single_post.save()      # and save it
        context_dict = {
            'single_post' :single_post,
        }

        return render(request, 'main/post.html', context_dict)
#for category page
def category(request, category_name_slug):
    try:

                category = Category.objects.get(slug=category_name_slug)
                sort = request.GET["sort"].strip()
                sort_method = SortMethods[sort]
                page = request.GET["page"].strip()
    except KeyError:
                sort_method = SortMethods.score
                page = 1

    if sort_method == SortMethods.date:
                thread_list = Post.objects.filter(category=category).order_by("-pub_date")
    else:
                thread_list = Post.objects.filter(category=category)
                thread_list = sorted(thread_list, key=lambda x: x.get_score(), reverse=True)

    paginator = Paginator(thread_list, 30)

    try:
                posts = paginator.page(page)
    except PageNotAnInteger:
                posts = paginator.page(1)
    except EmptyPage:
                posts = paginator.page(paginator.num_pages)

    context = {
                "posts": posts,
                "pages": paginator.page_range,
                "sort": sort_method.name,
                "categories":category,
              "cat_name_slug":category_name_slug,
        }
    return render(request, "main/index.html", context)

Answer 1

首先要注意的是，您有一个 空 slug:

Reverse for 'category' with arguments '(u'',)' and keyword arguments '{}' not found

一个问题是你如何定义 categories - .all() 是一个方法，调用它:

categories = Category.objects.all()
                             HERE^

此外，您应该检查您的类别是否生成了非空 slug。

NoReverseMatch at/ something wrong with url with slug

NoReverseMatch at/ something wrong with url with slug

python

django

django-urls

django-views