Odoo中的Map

在Odoo源代码中，常常可以看到使用ORM的map。

Model.mapped(func)

Parameters参数：func (callable or str) – a function or a dot-separated sequence of field names

Returns返回：self if func is falsy, result of func applied to all self records.

Return type返回类型：list or recordset

如下代码示例：

# returns a list of names
records.mapped('name')

# returns a recordset of partners
records.mapped('partner_id')

# returns the union of all partner banks, with duplicates removed
records.mapped('partner_id.bank_ids')

# returns a list of summing two fields for each record in the set
records.mapped(lambda r: r.field1 + r.field2)

　　如下面代码，使用map来统计订单行的产品成本：

1 @api.depends('order_line.product_uom_qty','order_line.purchase_price')
2     def _compute_product_cost(self):
3         for order in self:
4             if order.order_line:
5                 order.total_product_cost = sum(order.order_line.mapped(lambda r: r.purchase_price * r.product_uom_qty))

官网文档链接