session timeout in django

# create and keep  in middleware.py

from django.contrib.auth import logout
from django.contrib import messages
import datetime
from django.shortcuts import redirect

import settings

class SessionIdleTimeout:
    def process_request(self, request):
        if request.user.is_authenticated():
            current_datetime = datetime.datetime.now()
            if ('last_login' in request.session):
                last = (current_datetime - request.session['last_login']).seconds
                if last > settings.SESSION_IDLE_TIMEOUT:
                    logout(request, login.html)
            else:
                request.session['last_login'] = current_datetime
        return None




# this is in settings.py


TIME= 20   #  //four hours  or your time
SESSION_SERIALIZER = 'django.contrib.sessions.serializers.PickleSerializer'
SESSION_EXPIRE_AT_BROWSER_CLOSE= True
SESSION_COOKIE_AGE = TIME    #//change expired session
SESSION_IDLE_TIMEOUT = TIME # //logout