Django 2.0:/url/ (/pledges/group/7/) 处的 NoReverseMatch

Django 2.0: NoReverseMatch at /url/ (/pledges/group/7/)

我刚从 Django 1.11 升级到 2.0。这些是我拥有的一个 Django 应用程序的网址:

urlpatterns = [
    url(r'^logout/$', views.logout, name='logout'),
    url(r'^$', views.home, name='home'),
    url(r'^pledge/(?P<group_id>[0-9]+)/$',
        views.pledge, name='pledge_by_group'),
    # I have more urls, but I have omitted them since they are not relevant
    url(r'^404/$', views.bad_request, name='404')
]

升级后,我检查一切正常。然后,我改变了:

url(r'^pledge/(?P<group_id>[0-9]+)/$', views.pledge, name='pledge_by_group')

至:

url('pledge/<int:group_id>/', views.pledge, name='pledge_by_group'),

为了利用 Django 2.0 中的 simplified URL routing syntax。但是,当我尝试访问 http://localhost:8000/pledges/group/7/:

时出现以下错误

NoReverseMatch at /pledges/group/7/ Reverse for 'pledge_by_group' with keyword arguments '{'group_id': '7'}' not found. 1 pattern(s) tried: ['pledge//']

这是我的观点:

@login_required(redirect_field_name='')
def group_pledge(request, group_id):
    """Some docstring..."""
    # Some code that is not relevant to the problem

    context = {
        'pledge_url':  reverse('pledges:pledge_by_group',
                        kwargs={'group_id': group_id}),
    } # context has more values, but for practical reasons I don't include them

    return render(request, 'pledges/home.html', context)

根据报错,问题出在这一行:

reverse('pledges:pledge_by_group', kwargs={'group_id': group_id})

有人能告诉我这是怎么回事以及如何解决吗?

新语法需要使用path函数。例如:

from django.urls import path

...
path('pledge/<group_id>/', views.pledge, name='pledge_by_group'),