[Answer]-Django Name Groups Urls.py

You have set the brackets for the named groups wrong, try like this:

url(r'^activate/(?P<confirmation_code>[\w]{1,33})/(?P<username>\[\w]+)/$', 'views.activate', {}, 'activate')

HTH 🙂

Update:
Try like above if your token is up to 33 characters (alpha-numeric).