[Answered ]-NoReverseMatch at /rango/ newbie got stuck in tango w django tutorial

The - dash in the other-frameworks string does not match the (alphanumeric and underscore) \w.

Change the regex in the url to the [\w-]+:

url(r'^category/(?P<category_name_url>[\w-]+)/$', views.category,
                                                  name='category'),