Django URL mapping - NameError: name X is not defined

Question

[A similar question was asked, but not marked as answered, here. I considered continuing that thread but the website told me I'm only supposed to post an answer, so it seems I have to start a new topic.] I'm trying to follow this tutorial and I'm having problems with the URL mapping. Specifically with the part described as "So best practice is to create an “url.py” per application and to include it in our main projects url.py file". The relevant, I hope, part of the folder structure, which arose by following steps of the tutorial to the letter (if possible; usage of the 'patterns' module was impossible for example) and using Django 1.10 is the following:

myproject/
  myapp/
    urls.py
    views.py
  myproject/
    urls.py

The myproject/urls.py is as follows:

from django.conf.urls import include, url

from django.contrib import admin
admin.autodiscover()

from myapp.views import hello

urlpatterns = [
url(r'^admin/', include(admin.site.urls)),
url(r'^myapp/', include(myapp.urls)),
]

The myapp/urls.py is as follows:

from django.conf.urls import include, url

urlpatterns = [
    url(r'^hello/', myapp.views.hello),
]

The myapp/views.py is as follows:

from django.shortcuts import render

def hello(request):
   return render(request, "hello.html", {})

However, running 'python manage.py runserver' results in the following error:

url(r'^myapp/', include(myapp.urls)),
NameError: name 'myapp' is not defined

INSTALLED_APPS in settings.py contains 'myapp'.

I'd be greatful for any tips on how to deal with the NameError! [Or any tips whatsoever that anyone might consider to be helpful!]

Answer 1

You have the NameError because you are referencing myapp in myproject/urls.py but haven't imported it.

The typical approach in Django is to use a string with include, which means that the import is not required.

url(r'^myapp/', include('myapp.urls')),

Since you have move the hello URL pattern into myapp/urls.py, you can remove from myapp.views import hello from myproject/urls.py.

Once you've made that change, you will get another NameError in myapp/urls.py. In this case, a common approach is to use a relative import for the app's views.

from django.conf.urls import url
from . import views

urlpatterns = [
    url(r'^hello/$', views.hello),
]

Answer 2

Make sure you have imported following modules to urls.py.

from django.conf.urls import url
from django.contrib import admin

Answer 3

in django 2.0 use these

from django.contrib import admin
from django.urls import path
from first_app import views

urlpatterns = [


    path('',views.index, name="index"),

    path('admin/', admin.site.urls),
]

Answer 4

your app URL has to be a string so, here is how the code should look like.

from django.conf.urls import include, url

from django.contrib import admin admin.autodiscover()

from myapp.views import hello

urlpatterns = [
url(r'^admin/', include(admin.site.urls)),
url(r'^myapp/', include('myapp.urls')),
]

also, note that from python 2 upward the regular expression is not needed. change URL to path from django.conf.URLs import include path

from Django.contrib import admin admin.autodiscover()

from myapp.views import hello

urlpatterns = [
path('^admin/', include(admin.site.urls)),
path('^myapp/', include('myapp.urls')),
 ]