如何解决 NoReverseMatch，找不到参数？ （姜戈）

Question

编辑：我能够通过如下修改 view.py 来实现所需的行为

urlpatterns = [
    path("", views.index, name="index"),
    path("wiki/<str:entry>", views.entry, name="entry"),
    path("edit/<str:page>", views.edit, name="edit"),
    path("new", views.new, name="new"),
    path("edit/CSS", views.edit, name="edit")
]

但是我不知道，为什么会这样！！！？？？注意：它不仅适用于条目'CSS'，还适用于其他条目。

模板编辑.html

{% extends "encyclopedia/layout.html" %}

{% block title %}
    Edit
{% endblock %}
    
{% block body %}
    <form action="{% url 'edit' %}" method="POST">
        {% csrf_token %}
        <table border="1">
            {{ form_newpage }}
        </table>
        <button type="submit">Save Page</button>
    </form>
    
{% endblock %}

---

我是 Django 新手。我收到以下错误：NoReverseMatch: Reverse for 'edit' with no arguments not found. 1 pattern(s) tried: ['edit/(?P<page>[^/]+)$']

指定：我正在建立一个类似维基百科的网站，现在想要允许编辑功能。因此我包括了

path("edit/<str:page>", views.edit, name="edit"),

在我的百科全书应用程序的 urls.py 中进入我的 urlpatterns。

对于编辑，views.py 看起来像这样：

def edit(request, page):
    return render(request, "encyclopedia/edit.html", {
        "form_newpage": NewPageForm(initial={'content': util.get_entry(page), 'title': page}),
        "form_searchwiki": SearchWikiForm()
    })

当我现在尝试访问 http://127.0.0.1:8000/edit/CSS - CSS 是该百科全书的有效条目时 - 我收到 NoReverseMatch 错误。在 Traceback 中，局部变量页面的值是 'CSS'，所以我不明白，为什么 Django 不将 'CSS' 识别为 url 中的正确参数。

get_entry 函数：

 def get_entry(title):
        """
        Retrieves an encyclopedia entry by its title. If no such
        entry exists, the function returns None.
        """
        try:
            f = default_storage.open(f"entries/{title}.md")
            return f.read().decode("utf-8")
        except FileNotFoundError:
            return None

完整追溯：

Traceback (most recent call last):
  File "/home/fed/.local/lib/python3.8/site-packages/django/core/handlers/exception.py", line 47, in inner
    response = get_response(request)
  File "/home/fed/.local/lib/python3.8/site-packages/django/core/handlers/base.py", line 179, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/fed/cs/cs50_web/wiki/encyclopedia/views.py", line 59, in edit
    return render(request, "encyclopedia/edit.html", {
  File "/home/fed/.local/lib/python3.8/site-packages/django/shortcuts.py", line 19, in render
    content = loader.render_to_string(template_name, context, request, using=using)
  File "/home/fed/.local/lib/python3.8/site-packages/django/template/loader.py", line 62, in render_to_string
    return template.render(context, request)
  File "/home/fed/.local/lib/python3.8/site-packages/django/template/backends/django.py", line 61, in render
    return self.template.render(context)
  File "/home/fed/.local/lib/python3.8/site-packages/django/template/base.py", line 170, in render
    return self._render(context)
  File "/home/fed/.local/lib/python3.8/site-packages/django/template/base.py", line 162, in _render
    return self.nodelist.render(context)
  File "/home/fed/.local/lib/python3.8/site-packages/django/template/base.py", line 938, in render
    bit = node.render_annotated(context)
  File "/home/fed/.local/lib/python3.8/site-packages/django/template/base.py", line 905, in render_annotated
    return self.render(context)
  File "/home/fed/.local/lib/python3.8/site-packages/django/template/loader_tags.py", line 150, in render
    return compiled_parent._render(context)
  File "/home/fed/.local/lib/python3.8/site-packages/django/template/base.py", line 162, in _render
    return self.nodelist.render(context)
  File "/home/fed/.local/lib/python3.8/site-packages/django/template/base.py", line 938, in render
    bit = node.render_annotated(context)
  File "/home/fed/.local/lib/python3.8/site-packages/django/template/base.py", line 905, in render_annotated
    return self.render(context)
  File "/home/fed/.local/lib/python3.8/site-packages/django/template/loader_tags.py", line 62, in render
    result = block.nodelist.render(context)
  File "/home/fed/.local/lib/python3.8/site-packages/django/template/base.py", line 938, in render
    bit = node.render_annotated(context)
  File "/home/fed/.local/lib/python3.8/site-packages/django/template/base.py", line 905, in render_annotated
    return self.render(context)
  File "/home/fed/.local/lib/python3.8/site-packages/django/template/defaulttags.py", line 446, in render
    url = reverse(view_name, args=args, kwargs=kwargs, current_app=current_app)
  File "/home/fed/.local/lib/python3.8/site-packages/django/urls/base.py", line 87, in reverse
    return iri_to_uri(resolver._reverse_with_prefix(view, prefix, *args, **kwargs))
  File "/home/fed/.local/lib/python3.8/site-packages/django/urls/resolvers.py", line 685, in _reverse_with_prefix
    raise NoReverseMatch(msg)
django.urls.exceptions.NoReverseMatch: Reverse for 'edit' with no arguments not found. 1 pattern(s) tried: ['edit/(?P<page>[^/]+)$']
[22/Dec/2020 17:20:16] "GET /edit/CSS HTTP/1.1" 500 153425

我现在尝试的（在views.py中的编辑功能内）是：

return HttpResponse("Hello, world!")

.. 这可以正常工作。

我认为，从我现在所读的内容来看，错误必须在 urls.py 中？！错误基本上是说编辑/ CSS 不匹配，什么时候应该匹配..？！

Answer 1

据我了解，您没有在上下文中传递页面，而是将其命名为标题，因此页面在您的 url 模板标签中没有任何价值

return render(request, "encyclopedia/edit.html", {
        "form_newpage": NewPageForm(initial={'content': util.get_entry(page), 'title': page}),
        "form_searchwiki": SearchWikiForm()
    })