from django.conf.urls import url

import core.views

urlpatterns = [
    url(r'^u/(?P<slug>[\w-]+)/$', core.views.run_fn, name="run_fn"),
]

@@ -92,12 +92,15 @@
 %5B%5Cw-
+%5C.
 %5D+)/
+?
 $', 

Handle period in url slugs