def _total_amount(self, cr, uid, ids, field_name, arg, context=None):

res = {}

partner_obj = self.pool.get('res.partner')

for value in self.browse(cr,uid,ids):

      amount+ = value.total_amount/10

return res

for line in partner_obj.browse(cr,uid,value.partner_id.id):

   partner_obj.write(cr,uid,[value.partner_id.id],{'points':amount})

return res

'amount_sold' : fields.function(_total_amount, method=True, string='Amount Sold', type='float',),