How can I filter some host via openstack.py

Hi all:

I use this https://github.com/ansible/ansible/blob/devel/contrib/inventory/openstack.py to get a dynamic inventory from openstack.

/etc/ansible/openstack.py --list will list all host which in a openstack project,but if I want skip some hosts that I dont want ansible to access,How can I do that?

seems there is no doc for this script. should I do some hack for this script?