Django reverse causing url circular import, why? - django

Question

I get this error:
The included urlconf 'fouraxis.urls' does not appear to have any
patterns in it. If you see valid patterns in the file then the issue
is probably caused by a circular import.
I know the url pattern has something in it, it looks like this:
from django.conf.urls import include, url
from django.contrib import admin
urlpatterns = [
url(r'^perfil/', include('clientes.urls'), namespace="cliente"),
url(r'^admin/', include(admin.site.urls))
]
clientes.urls:
from django.conf.urls import url
from django.contrib.auth import views as auth_views
from clientes import views
urlpatterns = [
# login
url(r'^login/$', auth_views.login, {'template_name': 'perfiles/login.html'}, name="login"),
url(r'^logout/$', auth_views.logout, {'template_name': 'perfiles/logged_out.html'}, name="login"),
url(r'^mi_perfil/$', views.mi_perfil, name="mi_perfil"),
url(r'^registro_usuario/$', views.RegistroUsuario.as_view(), name="registro_usuario")
]
The RegistroUsuario view looks like this:
class RegistroUsuario(FormView):
template_name = "perfiles/registro_usuario.html"
form_class = UserCreationForm
success_url = reverse("cliente:mi_perfil") # THIS REVERSE
def form_valid(self, form):
return redirect("cliente:mi_perfil")
context = {'form': UserCreationForm}
I understand I can replace the reverse with a plain-text url like this perfil/mi_perfil. But, I want to know why is this happening with reverse, I can't find the explanation on de docs. Also, using reverse is better cause it is dynamic (if anytime I change the url, it still works as long as it keeps its name).

Answer 1

The reverse() call is made when the view is imported, which is probably when the urlconf is first loaded. You need to use reverse_lazy() instead:
from django.core.urlresolvers import reverse_lazy
class RegistroUsuario(FormView):
template_name = "perfiles/registro_usuario.html"
form_class = UserCreationForm
success_url = reverse_lazy("cliente:mi_perfil") # THIS REVERSE
def form_valid(self, form):
return redirect("cliente:mi_perfil")
context = {'form': UserCreationForm}