First make sure you have SessionMiddleware and AuthenticationMiddleware middlewares added to your MIDDLEWARE_CLASSES setting.
The current user is in request object, you can get it by:
current_user = request.user
request.user will give you a User object representing the currently logged-in user. If a user isn't currently logged in, request.user will be set to an instance of AnonymousUser. You can tell them apart with the field is_authenticated, like so:
# Do something for authenticated users.
# Do something for anonymous users.
Hope it works!!