I have created a wizard which adds a product bundle to sale.order.line along with the quantity. The .py of wizard is hereby:

lass SaleView(models.TransientModel):
_name = "sale.order.wizard"

#list of field used in wizard given here
product_name = fields.Many2one("product.product", string="Product Name", required=True)
quantity = fields.Float(string="Quantity", default=1.0)


@api.multi
def button_send(self):
#this function is used to create a new product list in sale.order.line
#after clicking add pack button in wizard of sale.order.wizard
for line in self.product_name:
self.env['sale.order.line'].create({
'product_id': line.id,
'product_uom_qty': self.quantity,
'order_id': self._context.get('active_id')
})
return True            I want to update quantity when product_uom_qty in sale.order.line is changed. Does anyone have any idea how to do it. Please help me. Thanks in advance..