urlpatterns = [url('^$', wrap(self.index), name='index'), url('^login/$',
    self.login, name='login'), url('^logout/$', wrap(self.logout), name=
    'logout'), url('^password_change/$', wrap(self.password_change,
    cacheable=True), name='password_change'), url('^password_change/done/$',
    wrap(self.password_change_done, cacheable=True), name=
    'password_change_done'), url('^jsi18n/$', wrap(self.i18n_javascript,
    cacheable=True), name='jsi18n'), url(
    '^r/(?P<content_type_id>\\d+)/(?P<object_id>.+)/$', wrap(
    contenttype_views.shortcut), name='view_on_site')]
Why do some includes in Django need strings, and others variable names?