Django 中的模板渲染 (NoReverseMatch) 期间出错

Question

I am trying to submit the form to my view:

in trending.html:

{% extends 'djangobin/base.html' %}

{% load static %}
{% load humanize %}

{% block title %}
    Trending {{ lang.name }} Snippets - {{ block.super }}
{% endblock %}

{% block main %}

    <h5><i class="fas fa-chart-line"></i> Trending {{ lang.name }} Snippets</h5>
    <hr>

    <table class="table">
        <thead>
        <tr>
            <th>Title</th>
            <th>Date</th>
            <th>Hits</th>
            <th>Language</th>
            <th>User</th>
        </tr>
        </thead>
        <tbody>

        {% for snippet in snippets %}
            <tr>
                <td><i class="fas fa-globe"></i>
                    <a href="{{ snippet.get_absolute_url }}">{{ snippet.title }}</a>
                </td>
                <td title="{{ snippet.created_on }}">{{ snippet.created_on|naturaltime }}</td>
                <td>{{ snippet.hits }}</td>
                <td><a href="{% url 'trending_snippets' snippet.language.slug  %}">{{ snippet.language }}</a></td>
                {% if not snippet.user.profile.private %}
                    <td><a href="{{ snippet.user.profile.get_absolute_url }}">{{ snippet.user.username|title }}</a></td>
                {% else %}
                    <td>-</td>
                {% endif %}

            </tr>
        {% empty %}
            <tr class="text-center">
                <td colspan="4">There are no snippets.</td>
            </tr>
        {% endfor %}

        </tbody>
    </table>

{% endblock %}

in views.py:

from django.shortcuts import HttpResponse, render, redirect, get_object_or_404, reverse
from .forms import SnippetForm
from .models import Language, Snippet

def trending_snippets(request, language_slug=''):
    lang = None
    snippets = Snippet.objects
    if language_slug:
        snippets = snippets.filter(language__slug=language_slug)
        lang = get_object_or_404(Language, slug=language_slug)
    snippets = snippets.all()
    return render(request, 'djangobin/trending.html', {'snippets': snippets, 'lang': lang})

in urls.py:

from django.conf.urls import url
from . import views as views
urlpatterns = [
    url('^trending/$', views.trending_snippets, name='trending_snippets'),
    url('^trending/(?P<language_slug>[\w]+)/$', views.trending_snippets, name='trending_snippets'),
]

I got the following error:

NoReverseMatch at /trending/ Reverse for 'trending_snippets' with arguments '('c-sharp',)' not found. 2 pattern(s) tried: ['trending/(?P[\w]+)/$', 'trending/$']

Exception Type: NoReverseMatch

Error during template rendering

Reference website: overiq.com

Reference website Link: https://overiq.com/django-1-11/creating-trending-snippet-page/

Python version: 3.8.2

Django version: 3.0.5

OS: Windows 8.1(32 bit)

Answer 1

To match c-sharp , which contains a hyphen, you need to change [\w] to [-\w] .

url('^trending/(?P<language_slug>[-\w]+)/$', views.trending_snippets, name='trending_snippets'),

Answer 2

Since it's a slug field you're matching, you can use the built-in slug path converter Django provides to match it by using path instead of url .

Change:

url('^trending/(?P<language_slug>[\w]+)/$', views.trending_snippets, name='trending_snippets'),

to:

path('trending/<slug:language_slug>)/', views.trending_snippets, name='trending_snippets'),

Note that slug: matches hyphens, underscores, and also ASCII letters and numbers.

url() is just an alias to re_path() and may be deprecated in the future , so you should change your code accordingly.