eiru_study_features/models/res_partner.py

# -*- coding: utf-8 -*-

from openerp import models, fields, api

class ResPartnerMedicalFeature(models.Model):
    _inherit = 'res.partner'

    is_medic = fields.Boolean()
    medic = fields.Many2one(
        'res.partner',
        string='Doctor',
        ondelete='restrict',
        domain=[('is_medic','=',True)]
    )

    study_feature_ids = fields.One2many(
        'study.feature',
        'partner_id',
        string='Medical Feature',
    )
    study_feature_count = fields.Integer(
        string='Numero de Estudios',
        compute='_get_study_features_count',
    )

    @api.one
    @api.depends('study_feature_ids')
    def _get_study_features_count(self):
        self.study_feature_count = len(self.study_feature_ids)