URLs and views

2 min read Quiz included

A view is a Python function that takes a request and returns a response. A URL pattern connects an address to a view.

Your first view

In an app (created with python manage.py startapp courses, and added to INSTALLED_APPS), edit courses/views.py:

Python

from django.http import HttpResponse

def home(request):
    return HttpResponse("<h1>Welcome to CodeMIRAI</h1>")

def about(request):
    return HttpResponse("We teach coding in small steps.")

Connecting URLs

Create courses/urls.py:

Python

from django.urls import path
from . import views

urlpatterns = [
    path("", views.home, name="home"),
    path("about/", views.about, name="about"),
]

Then include the app's URLs in the project's config/urls.py:

Python

from django.contrib import admin
from django.urls import include, path

urlpatterns = [
    path("admin/", admin.site.urls),
    path("", include("courses.urls")),
]

Now / shows the home view and /about/ the about view.

Capturing values from the URL

Angle brackets capture part of the URL and pass it to the view as an argument:

Python

# courses/urls.py
urlpatterns = [
    path("", views.home, name="home"),
    path("courses/<slug:slug>/", views.course_detail, name="course-detail"),
    path("lessons/<int:number>/", views.lesson, name="lesson"),
]

Python

# courses/views.py
from django.http import HttpResponse

def course_detail(request, slug):
    return HttpResponse(f"You are viewing the course: {slug}")

def lesson(request, number):
    return HttpResponse(f"Lesson number {number}, doubled is {number * 2}")

Converters check and convert the value:

Converter	Matches	Example
`str`	any text without `/` (the default)	`<str:name>`
`int`	zero or positive whole numbers	`<int:id>`
`slug`	letters, numbers, hyphens, underscores	`<slug:slug>`
`uuid`	a UUID	`<uuid:token>`

/lessons/7/ calls lesson(request, number=7) with 7 as an int; /lessons/abc/ doesn't match at all, so Django returns a 404.

Names instead of hard-coded URLs

The name= lets you build URLs from code, so changing a URL later doesn't break links:

Python

from django.urls import reverse

reverse("course-detail", args=["python"])    # "/courses/python/"

In templates you'll write {% url 'course-detail' 'python' %}.

Finished this lesson?Mark it complete to earn +20 XP and move your progress on.