openstack swift authentication problem in 0.16.0

cls = get_driver(Provider.OPENSTACK_SWIFT)

driver = cls("user", "password" , ex_force_auth_url="url", ex_tenant_name="tenant", ex_force_auth_version="2.0_password",ex_force_service_type='object-store', ex_force_service_name='swift', ex_force_service_region="region")

driver.list_containers()

/home/ubuntu/verify/local/lib/python2.7/site-packages/libcloud/common/openstack.pyc in morph_action_hook(self, action)
    253
    254     def morph_action_hook(self, action):
--> 255         self._populate_hosts_and_request_paths()
    256         return super(OpenStackBaseConnection, self).morph_action_hook(action)
    257

/home/ubuntu/verify/local/lib/python2.7/site-packages/libcloud/common/openstack.pyc in _populate_hosts_and_request_paths(self)
    297             self.service_catalog = osc
    298
--> 299         url = self._ex_force_base_url or self.get_endpoint()
    300         self._set_up_connection_info(url=url)
    301

/home/ubuntu/verify/local/lib/python2.7/site-packages/libcloud/storage/drivers/cloudfiles.pyc in get_endpoint(self, *args, **kwargs)
    139                 name=self._service_name, region=self._service_region)
    140
--> 141         if PUBLIC_ENDPOINT_KEY in endpoint:
    142             return endpoint[PUBLIC_ENDPOINT_KEY]
    143         else:

TypeError: argument of type 'OpenStackServiceCatalogEntryEndpoint' is not iterable