链接不工作，抛出NoReverseMatchError

Question

NoReverseMatch at /category/1/
Reverse for 'category' with arguments '('',)' not found. 1 pattern(s) tried: ['category/(?P<category_id>[0-9]+)/$']

从主页导航到站点类别时显示此错误。在谷歌上，我发现我的url与模板中的url不匹配，django报告了它。但是我仍然不明白哪里出了问题，因为所有的东西都是为了匹配urls.py模板而写的。

urls . py (app文件夹)

from django.urls import path
from .views import *

urlpatterns = [
path('', home_page, name='home_page'),
path('category/<int:category_id>', get_category, name='category'),
path('news/<slug:slug>', view_news, name='news'),
]

urls . py(项目文件夹)

import debug_toolbar
from django.contrib import admin
from django.urls import include, path
from django.conf import settings
urlpatterns = [
path('admin/', admin.site.urls),
path('', include('news.urls')),
path('ckeditor/', include('ckeditor_uploader.urls')),
path('__debug__/', include(debug_toolbar.urls)),
]

base.html

{% load news_tags %}
{% get_all_categories as categoies %}
{% for category in categoies %}
<li><a href="{% url 'category' category.pk %}" class="nav-link px-2" style="color: rgb(179, 179, 179);">{{ category.title }}</a></li>
{% endfor %}

index . html(主页)

{% for item in page_obj %}
<div class="card mb-5">
<div class="card-header">
<div class="category_name"> <a href="{% url 'category' item.category_id %}" style="text-decoration: none; color: rgb(93, 92, 92);">{{ item.category }}</a> - {{ item.created_at }}</div>
</div>
<a href="/news/{{ item.slug }}" style="text-decoration: none; color: rgb(26, 25, 25);">
<div class="card-body">
<h3 class="card-title">{{ item.title }}</h3>
<p class="card-text">{{ item.content|linebreaks|truncatewords:50 }}</p>
</div>
</a>
</div>
{% endfor %}

views.py

def home_page(request):
all_publicated_blogs = News.objects.filter(is_published=True,)
return render(request, 'news/index.html', 
{'page_obj': Pagination(request, all_publicated_blogs).pagination(10),})

def get_category(request, category_id):
news_by_category = News.objects.filter(category_id=category_id, is_published=True)
one_news = news_by_category[0]

return render(request, 'news/category.html', 
{'page_obj': Pagination(request, news_by_category).pagination(10), 'news': one_news,})

models.py

from django.db import models
from ckeditor.fields import RichTextField

class News(models.Model):
title = models.CharField(max_length=50,verbose_name='Заголовок',)
content = RichTextField()
created_at = models.DateTimeField(auto_now_add=True,verbose_name='Дата Создания')
updated_at = models.DateTimeField(auto_now=True)
is_published = models.BooleanField(default=False, verbose_name='Опубликовано')                    
category = models.ForeignKey('Category', on_delete=models.PROTECT, null=True, verbose_name='Категория')
slug = models.SlugField(verbose_name='URL', max_length=40, unique=True,)

def __str__(self):
return self.title
class Meta:
verbose_name = 'Новость'
verbose_name_plural = 'Новости'
ordering = ['-created_at']

class Category(models.Model):
title = models.CharField(max_length=50, db_index=True,
verbose_name='Название категории')                         
def __str__(self):
return self.title
class Meta:
verbose_name = 'Категорию'
verbose_name_plural = 'Категории'
ordering = ['id']

news_tags.py

from django import template
from news.models import Category

register = template.Library()

@register.simple_tag()
def get_all_categories():
return Category.objects.all()

category.html

{% get_all_categories as categoies %}
{% for category in categoies %}
{% if category == news.category %}
<li><a href="{% url 'category' category_id=category.pk %}" class="nav-link px-2" style="color: white;display: inline; padding: 17px 6px; border-bottom: solid 5px #707990;">{{ category.title }}</a></li>
{% else %}
<li><a href="{% url 'category' category_id=category.pk %}" class="nav-link px-2" style="display: inline; padding: 0px 6px;">{{ category.title }}</a></li>
{% endif %}
{% endfor %}

Answer 1

我认为index.html在url标签中对类别的引用是关闭的。将href="{% url 'category' item.category_id %}"改为href="{% url 'category' item.category.id %}"