class test1(models.Model):
    """docstring for ClassName"""
    _name = 'test.test1'
    _rec_name = 'name'

    id = fields.Char(string='ID Test 1', required=True)
    name = fields.Char(string='Name ID Test 1', required=True)
    price = fields.Float(string='Price ID Test 1', required=True)


class test2(models.Model):
    _name = 'test.test2'

    test1_name = fields.Many2one("test.test1", "List test 1", required=True)
    amount = fields.Integer(string='Amount', required=True, default='1')
    mymoney = fields.Float(string="Money", readonly=True)# mymoney = amount * price

    @api.onchange("test1_name")
    def onchange_test2(self):
        #self.mymoney = ?????  <============

How to get data "price" from test1 classes for caculate?

Thanks