Python Django NoReverseMatch名称空间错误

我的URL.py中有以下内容：

urlpatterns = patterns('',
                       url(r'^ding/', include('ding.urls', namespace='ding', app_name='ding')),

在my ding/url.py中：

urlpatterns = patterns('',
                       url(r'^$', views.sign_in, name='sign_in'),
                       url(r'^connect/$', views.connect, name='connect'),
                       url(r'^disconnect/$', views.disconnect, name='disconnect'),
                       #url(r'^disconnect/sign_in/$', RedirectView.as_view(url=reverse('sign_in')), name="disconnect_sign_in"),
                       url(r'^search$', views.search, name='search'),
                       url(r'^parsed_query/(?P<query>.+)/(?P<scroll_num>(\-|)\d+)/$', views.get_search_results, name='get_search_results'),
                       url(r'^parsed_query/', views.parsed_query, name='parsed_query'),
                       url(r'^parsed_query_redirect/', views.parsed_query_redirect, name='parsed_query_redirect'),
)

导致NoReverseMatch错误

有什么建议吗

reverse('ding:sign_in')

参考：

确保您知道应用程序命名空间和实例命名空间之间的区别：
我发现很少需要这两种方法（但当然有很多这样的用例）

reverse('ding:sign_in')