@api.multi
def _compute_price_reduce(self):
    for record in self:
        product = record.product_id
        discount = ((product.lst_price and ((product.lst_price - product.price) / product.lst_price)) or 0.0)
        record.price_reduce = ((1.0 - discount) * record.price)
@api.multi
def _compute_price_reduce(self):
    for record in self:
        product = record.product_id
        discount = ((product.lst_price and ((product.lst_price - product.price) / product.lst_price)) or 0.0)
        record.price_reduce = ((1.0 - discount) * record.price)