Añadir Suma de cantidad de líneas de compras

models/purchase.py

@@ -3,14 +3,24 @@
 from openerp import tools, api
 from openerp import api, fields, models, _
 
-class PickingTotalQty(models.Model):
+# class PickingTotalQty(models.Model):
+#     _inherit = 'purchase.order'
+#
+#     tot_purchase_qty = fields.Float(compute='_calculate_purchase_qty', string='Total Cantidad Comprado', help="Total cantidad comprado")
+#
+#     def _calculate_purchase_qty(self):
+#         for rs in self:
+#             sumqty = 0
+#             for line in rs.order_line:
+#                 sumqty += line.product_qty
+#         rs.tot_purchase_qty = sumqty
+
+class PurchaseOrder(models.Model):
     _inherit = 'purchase.order'
 
-    tot_purchase_qty = fields.Float(compute='_calculate_purchase_qty', string='Total Cantidad Comprado', help="Total cantidad comprado")
+    tot_purchase_qty = fields.Float(string='Cantidad de Productos de Compra', compute='_calculate_purchase_qty')
 
+    @api.depends('order_line.product_qty')
     def _calculate_purchase_qty(self):
-        for rs in self:
-            sumqty = 0
-            for line in rs.order_line:
-                sumqty += line.product_qty
-        rs.tot_purchase_qty = sumqty
+        for order in self:
+            order.tot_purchase_qty = sum(order.order_line.mapped('product_qty'))