Django 2.0 path error ?: (2_0.W001) has a route that contains '(?P<', begins with a '^', or ends with a '$'

Question

I'm trying to create the back-end code for a music application on my website.

I have created the correct view in my views.py file (in the correct directory) as shown below:

def detail(request, album_id):     return HttpResponse("<h1>Details for Album ID:" + str(album_id) + "</h1>") 

However, when creating the URL or path for this (shown below)

#/music/71/ (pk) path(r'^(?P<album_id>[0-9])/$', views.detail, name='detail'), 

I am experiencing a warning on my terminal stating:

?: (2_0.W001) Your URL pattern '^(?P<album_id>[0-9])/$' [name='detail'] has a route that contains '(?P<', begins with a '^', or ends with a '$'. This was likely an oversight when migrating to django.urls.path(). 

And whenever the /music/ (for which the path works) is followed by a number, such as /music/1 (which is what I want to be able to do) the page cannot be found and the terminal gives the above warning.

Answer 1

The new path() syntax in Django 2.0 does not use regular expressions. You want something like:

path('<int:album_id>/', views.detail, name='detail'), 

If you want to use a regular expression, you can use re_path().

re_path(r'^(?P<album_id>[0-9])/$', views.detail, name='detail'), 

The old url() still works and is now an alias to re_path, but it is likely to be deprecated in future.

url(r'^(?P<album_id>[0-9])/$', views.detail, name='detail'), 

Answer 2

Just to add to what @alasdair mentioned, I added re_path as part of the include and it works fine. Here is an example

Add re_path to your import (for django 2.0)

from django.urls import path, re_path  urlpatterns = [     path('admin/', admin.site.urls),     re_path(r'^$', home, name='home'),  ]