Django Middleware to choose language based on subdomain

language.py

import logging

from django.utils import translation
from django.conf import settings

class DomainBasedLanguageMiddleware(object):
    """
    Set the language for the site based on the subdomain the request
    is being served on. For example, serving on 'fr.domain.com' would
    make the language French (fr).
    """

    def process_request(self, request):
        host = request.get_host()

        if host in settings.LANGUAGE_DOMAINS:
            lang = settings.LANGUAGE_DOMAINS.get(host)
            logging.debug("Choosing language: {0}".format(lang))
            translation.deactivate()
            translation.activate(lang)
            request.LANGUAGE_CODE = lang

settings.py

# Add this setting with real hostnames.

LANGUAGE_DOMAINS.update({'127.0.0.1:8000':'en','127.0.0.1:8001':'en_GB'})