OOP Python向基類添加一些屬性嗎？

Question

我正在使用python學習OOP。嘗試使用小型控制台應用程序Stock

class Stock(object):

    def __init__(self, stockName, stockLimit, inStock, rentPrice):

        self.stockName  = stockName   # private
        self.stockLimit = stockLimit  # private
        self.inStock    = inStock     # private
        self.rentPrice  = rentPrice   # private

    def inputStock(self, nProduct):

        if(nProduct >= (self.stockLimit - self.inStock)):
            self.inStock = self.stockLimit
        else:
            self.inStock += nProduct 

    def invoice(self, nDay):
        return self.rentPrice * nDay


class StockProduct(Stock):

    def __init__(self, factor):
        # the base-class constructor:
        Stock.__init__(self, stockName, stockLimit, inStock, rentPrice)
        self.factor = factor # Extra for this stock

    def invoice(self, nDay):
        return Stock.invoice(self, nDay) * self.factor

class StockMaterial(Stock):

    def __init__(self,factor):
        # the base-class constructor:
        Stock.__init__(self, stockName, stockLimit, inStock, rentPrice)
        self.factor = factor # Extra for this stock

    def invoice(self,nDay):
        return Stock.invoice(self, nDay)*self.factor

if __name__ == "__main__":

    N = nDay = 0
    myStock = Stock("stock111", 500, 200, 400000)
    N = float(raw_input("How many product into stock: "+str(myStock.stockName)+" ? "))
    myStock.inputStock(N)
    nDay = int(raw_input("How many days for rent : "+str(myStock.stockName)+" ? "))
    print "Invoice for rent the stock: "+str(myStock.stockName)+ " = "+ str(myStock.invoice(nDay))

    StockProduct = StockProduct("stock222",800, 250, 450000, 0.9)

    N = float(raw_input("How many product into stock: "+str(StockProduct.stockName)+" ? "))
    StockProduct.inputStock(N)
    nDay = int(raw_input("How many days for rent : "+str(StockProduct.stockName)+" ? "))
    print "Invoice for rent the stock: "+str(StockProduct.stockName)+ " = "+ str(StockProduct.invoice(nDay))

我有兩個問題：

1. 用我的方法invoice ，如何在python中進行方法重載？

2. 我在孩子中添加了一些屬性，但收到以下錯誤消息：

    StockProduct = StockProduct("stock222",800, 250, 450000, 0.9) TypeError error: __init__() takes exactly 2 arguments (6 given) 

我應該在這里做什么？

有人可以幫我嗎？

預先感謝

Answer 1

1. 派生類中超載的invoice應該可以正常工作。

2. 您的基類構造函數需要具有所有參數，因此：

    class StockProduct(Stock): def __init__(self, stockName, stockLimit, inStock, rentPrice, factor): # the base-class constructor: Stock.__init__(self, stockName, stockLimit, inStock, rentPrice) self.factor = factor def invoice(self, nDay): return Stock.invoice(self, nDay) * self.factor 

Answer 2

1-是的，您可以在python中進行方法重載。

2-您的子類更改了方法簽名。 您應該將其聲明為

def __init__(self, stockName, stockLimit, inStock, rentPrice, factor):

如果要使用父類的所有參數以及其他一些參數來構造它。