getting list of customer from res.partner on tree view

I am a new to python and openerp. the following code loads into openerp with no errors; however, I am not seeing any data from res.partner as I am expecting to. Can anyone see what the problem is in my code? class delivery_forcast(osv.osv): _name = "delivery.forcast" _inherit = "res.partner" _columns={ 'delivery_state': fields.selection([ ('scheduled','Scheduled'), ('delivered','Delivered')], 'Delivery Status', readonly=True, track_visibility='onchange'), 'est_delivery_date': fields.date('Estimated Delivery Date', readonly=False), 'container_size': fields.integer('Container Size', help='Container size to be filled in gallons',readonly=False), } delivery_forcast() delivery.forcast.treedelivery.forcastDelivery Forcastsdelivery.forcasttreetree[('customer','=',1)]