Hello,I have a question about the total cost for in the report , so the total cost is the sum of the price multiplied by the number of spare parts , how to calculate the total cost in py and RML

def _get_total(self, o):
        total = 0
        for o in o.line.parts_qty:
                total =(o.jumlah*o.parts_id.standard_price)
        return total