eiru_service/models/product_service_brand.py

# -*- encoding: utf-8 -*-
from openerp import models, fields, api, tools
from openerp.exceptions import ValidationError

class ProductServiceBrand(models.Model):
    _name = 'product.service.brand'

    name = fields.Char(string='Brand Name', required=True)
    description = fields.Text(string="Description")
    logo = fields.Binary('Logo File')
    product_service_ids = fields.One2many(
        'product.service',
        'product_service_brand_id',
    )
    product_service_count = fields.Integer(
        string='Numero de autos',
        compute='_get_product_service_count',
    )

    @api.one
    @api.depends('product_service_ids')
    def _get_product_service_count(self):
        self.product_service_count = len(self.product_service_ids)