def logout(request, next_page=None,
           template_name='registration/logged_out.html',
           redirect_field_name=REDIRECT_FIELD_NAME,
           current_app=None, extra_context=None):
    """
    Logs out the user and displays 'You are logged out' message.
    """
    auth_logout(request)

    if redirect_field_name in request.REQUEST:
        next_page = request.REQUEST[redirect_field_name]
        # Security check -- don't allow redirection to a different host.
        if not is_safe_url(url=next_page, host=request.get_host()):
            next_page = request.path

    if next_page:
        # Redirect to this page until the session has been cleared.
        return HttpResponseRedirect(next_page)

    current_site = get_current_site(request)
    context = {
        'site': current_site,
        'site_name': current_site.name,
        'title': _('Logged out')
    }
    if extra_context is not None:
        context.update(extra_context)
    return TemplateResponse(request, template_name, context,
        current_app=current_app)
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/django/contrib/auth/views.py/logout/original