'Fill empty columns in Packing Slip Item'

def update_item_details(self):

    if (not self.from_case_no):
        self.from_case_no = self.get_recommended_case_no()
    for d in self.get(u'items'):
        res = frappe.db.get_value(u'Item', d.item_code, [u'net_weight', u'weight_uom'], as_dict=True)
        if (res and (len(res) > 0)):
            d.net_weight = res[u'net_weight']
            d.weight_uom = res[u'weight_uom']
