title: django.http HttpResponseNotModified Python Code Examples

category: page

slug: django-http-httpresponsenotmodified-examples

sortorder: 50063

toc: False

sidebartitle: django.http HttpResponseNotModified

meta: Example Python code for using the HttpResponseNotModified object provided by Django in the django.http module.

[HttpResponseNotModified](https://docs.djangoproject.com/en/stable/ref/request-response/#django.http.HttpResponseNotModified)

([source code](https://github.com/django/django/blob/master/django/http/response.py))

returns the

[HTTP 304 status code](https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html)

from a [Django](/django.html) web application view. The HTTP 304 status code

indicates that the resource has not been modified since the client last requested

it.

[HttpResponseRedirect](/django-http-httpresponseredirect-examples.html)

and

[HttpResponsePermanentRedirect](/django-http-httpresponsepermanentredirect-examples.html)

are other types of 300-level HTTP status codes that can be

sent as a response by your Django application.

[wagtail](https://github.com/wagtail/wagtail)

([project website](https://wagtail.io/)) is a fantastic

[Django](/django.html)-based CMS with code that is open source

under the

[BSD 3-Clause "New" or "Revised" License](https://github.com/wagtail/wagtail/blob/master/LICENSE).

[**wagtail / wagtail / utils / sendfile_streaming_backend.py**](https://github.com/wagtail/wagtail/blob/master/wagtail/utils/sendfile_streaming_backend.py)

import os

import re

import stat

from email.utils import mktime_tz, parsedate_tz

from wsgiref.util import FileWrapper

~~from django.http import HttpResponseNotModified, StreamingHttpResponse

from django.utils.http import http_date

def sendfile(request, filename, **kwargs):

# Respect the If-Modified-Since header.

statobj = os.stat(filename)

if not was_modified_since(request.META.get('HTTP_IF_MODIFIED_SINCE'),

statobj[stat.ST_MTIME], statobj[stat.ST_SIZE]):

~~ return HttpResponseNotModified()

response = StreamingHttpResponse(FileWrapper(open(filename, 'rb')))

response["Last-Modified"] = http_date(statobj[stat.ST_MTIME])

return response

def was_modified_since(header=None, mtime=0, size=0):

"""

try:

if header is None:

raise ValueError

matches = re.match(r"^([^;]+)(; length=([0-9]+))?$", header,

re.IGNORECASE)

header_date = parsedate_tz(matches.group(1))

if header_date is None:

raise ValueError

header_mtime = mktime_tz(header_date)

header_len = matches.group(3)

if header_len and int(header_len) != size:

raise ValueError

if mtime > header_mtime:

raise ValueError

except (AttributeError, ValueError, OverflowError):

return True

return False

[HttpResponseRedirect](https://docs.djangoproject.com/en/stable/ref/request-response/#django.http.HttpResponseRedirect)

* [django.http HttpResponseNotModified](/django-http-httpresponsenotmodified-examples.html)

<a href="/django-http-httpresponsenotmodified-examples.html">HttpResponseNotModified</a>,