[Django]-Reverse for 'edit_user' with arguments '(2L,)' and keyword arguments '{}' not found. 0 pattern(s) tried: []

You have name='account_update' in your URL pattern, but are trying to reverse it using 'mylibrary:edit_user'.

You need to change one of them to match the other, for example:

url(r'^(?P<pk>[\-\w]+)/accounts/update/$', views.edit_user, name='edit_user'),