数组中的python循环添加单个项目价格

Question

我有以下代码主要工作。我只需要它允许用户输入“插件”，直到他们输入sentinel值退出循环，并让它添加选择。这是一个课堂作业，但这是所有我有困难。任何帮助都将不胜感激。你知道吗

    #start

def main():    #create a module - python function to hold main processing

    #declarations

    addinArray  = ["Whipped Cream", "Cinnamon", "Chocolate sauce", "Amaretto", "Irish whiskey"]
    priceArray = [0.89, 0.25, 0.59, 1.50, 1.75]  #this array holds the add-in prices

    loopFlag = ""  #sentinal value for looping
    cnt = 0
    COFFEECOST = 2  #constant to coffee cost

    addinName = ""
    totalCost = 0

    #input enter add-in name
    addinName = input("Enter on Keyboard Coffee Add-in (ex. Whipped Cream, Cinnamon, etc.) or Done to quit")
    while (addinName != "Done"):    #loop until addinName is Done
        while (cnt < len(addinArray)):
            if (addinName == addinArray[cnt]) :
                totalCost = priceArray[cnt] + totalCost
                print("Add-in ", addinName, " with a price of ", priceArray[cnt])
                print( "with a total add-in price so far of ", totalCost)
            cnt = cnt + 1  #increment counter for next element in array
        #end while

        addinName = input("Enter on Keyboard Coffee Add-in (ex. Whipped Cream, Cinnamon, etc.) or Done to quit")

    #end while
    totalCost = totalCost + COFFEECOST
    print("Total cost is: ", totalCost)
    main()
    #stop

Answer 1

我认为cnt = 0应该在第一个循环之后重置：

while (addinName != "Done"):    #loop until addinName is Done
    cnt = 0

如果没有这一点，在第一个外接程序之后，cnt就可以到达len(addinArray)，并且在为新的外接程序执行循环时永远不会出现第二个外接程序。你知道吗

Answer 2

我在本地运行了你的代码，发现了两件事。你知道吗

1. 您需要在嵌套的while循环之后将cnt变量重置为零，否则它将不会再次执行，因为条件cnd>5将始终是true。你知道吗

2. input()调用似乎抛出了一个错误，因此我测试了raw_input()，似乎正常工作。你知道吗

   希望这有帮助！