is not a valid regular expression: bad character in group name 'int:id' at position 13

Question

from django.conf.urls import url

from django.urls import  path, re_path
from . import views

urlpatterns = [

     path('', views.index, name='index'),
     #path('details/<int:id>/', views.details),
     #re_path(r'^details/(?P<int:id>\d+)/$', views.details),

]

Kindly assist me with the commented URLs patterns above. I am using Django 2.0. When I run the browser I get

django.core.exceptions.ImproperlyConfigured: "^details/(?P<int:id>\d+)/$" is not a valid regular expression: bad character in group name 'int:id' at position 13

My views.py is as below:

from django.shortcuts import render
from django.http import HttpResponse

from .models import Todo # to render todo items

def index(request):
    todos = Todo.objects.all() [:10] # define we want 10

    context = {
    'todos':todos   # pass it onto a template variable todos
    }
    return render(request, 'index.html', context)

def details(request, id):
    todo=Todo.objects.get(id=id)
    context = {
    'todo':todo   # pass it onto a template variable todos
    }
    return render(request, 'details.html', context)

and the web address displayed by the browser is:

http://127.0.0.1:8000/todo/details/<int:id>/

Answer 1

Your URL pattern using path() looks OK.

path('details/<int:id>/', views.details),

The re_path is incorrect, because <int:id> is not a valid. Remove the int:.

 re_path(r'^details/(?P<id>\d+)/$', views.details),

You only need to enable one of these, since they both match the same URLs, e.g. /details/5/.

As an aside, you may want to use get_object_or_404() instead of Todo.objects.get()`. This will handle the case when a todo with that id does not exist.

from django.shortcuts import get_object_or_404

todo = get_object_or_404(Todo, id=id)