試圖在兩個函數之間進行乘法運算？

Question

我是一名初學Python程序員，我正在創建一個卡路里計數器作爲實驗室。我想要做的是在列表中取出卡路里的整數值，並將其乘以列表中數量的整數值。

的代碼可以在下面

找到我想要做的基本上是

calories = int((conv(carbs, "c") + conv(fats, "f") + conv(protein, "p") * qtyList[c])) 

，但它說c沒有定義（這是因爲我不這樣做在顯示列表功能，但我不知道如何將c合併到本地的addItem函數中，或者首先如何完成此工作。）

有關程序的更多信息和tl; dr以及它需要做什麼：

• 歡迎菜單
• 顯示選項(a - add item, d - delete item, l - display list, q - quit)

• 時，它的a，接受字符串的項目名稱，INT項目數量，詮釋值轉化爲熱量，返回的熱量作爲一個int爲全局變量，然後乘以數量*卡路里項目總熱量

• d - 通過其在列表中

• 位置刪除列表中的項目- 顯示列表..簡單

• q - 退出

我很想知道，如果有人可以幫助我這個問題，雖然，而不是整個事情。謝謝。

# New Lab 7 

# define lists 
itemList = [] 
qtyList = [] 
calsList = [] 
totalCal = 0 

def conv(grams, kind): 
    if kind == "f": 
     return grams * 9 
    else: 
     return grams * 4 

def dispMenu(): 
    print ("a - add item") 
    print ("d - delete the item") 
    print ("l - display the list so far") 
    print ("q - quit") 

def addItem(): 
    carbs = 0 
    fats = 0 
    protein = 0 
    calories = 0 
    item = input("Item name: ") 
    if item.isspace() or len(item) == 0: 
     print("item must have a proper name") 
     return None # get me outta here 
    try: 
     qty = int(input("quantity: ")) 
     if qty <= 0: 
      print("quantity must be a positive number") 
      return None 
    except: 
     print("That was not a valid integer.") 
     return None 
    carbs = int(input("How many grams of carbs are displayed on your item? ")) 
    fats = int(input("How many grams of fats are displayed on your item? ")) 
    protein = int(input("How many grams of protein are displayed on your item? ")) 
    global calories 
    calories = int((conv(carbs, "c") + conv(fats, "f") + conv(protein, "p") * qtyList[c])) 
    calsList.append(calories) 
    itemList.append(item) 
    qtyList.append(qty) 
    print("Your item contains", calories, "calories.") 
    global totalCal 
    totalCal += calories 
    return totalCal 

def dispList(): 
    if len(itemList) == 0: 
     print("\nThere are no items in your list\n") 
    else: 

     print("\n\n\nThe items in your list are") 
     print("Itm\tItem\t\tQty\tCals") 

     totalQty = int(0) 
     for c in range(len(itemList)): 
      print(str(c+1)+".\t" + itemList[c], "\t", qtyList[c]) 
      totalQty += qtyList[c] 

     print("Total calories:\t{}".format(totalCal) + ".\n\n\n") 



def delItem(): 
    if len(itemList) == 0: 
     print("\nThere are no items in your list to delete\n") 
    else: 
     print("Please choose the item number to delete") 
     dispList() 
     choice = int(input("Delete item > ")) 

     if 1 <= choice <= len(itemList): 
      del itemList[choice - 1] 
      del qtyList[choice - 1] 
      print("Item Deleted") 
      dispList() 
     else: 
      print("\nThe value is out of range\n") 




# start the program 
print("Welcome to Clinton's Calorie Counter!") 
dispMenu() 
while True: 

    choice = input("> ") 

    if choice == "a": 
     addItem() 
     dispMenu() 
     continue 
    elif choice == "q": 
     dispList() 
     print("Goodbye!") 
     break 
    elif choice == "l": 
     dispList() 
     dispMenu() 
     continue 
    elif choice == "d": 
     delItem() 
     continue 

Answer 1

我懷疑你的意思是：

比

calories = int((conv(carbs, "c") + conv(fats, "f") + conv(protein, "p") * qty)) 

更多，你的意思是：

calories_per_item = int((conv(carbs, "c") + conv(fats, "f") + conv(protein, "p")) 
calories = calories_per_item * qty 

其他明智計算的數字是：carbs + fats + (protein * quantity)

也就是說，使用您剛剛向用戶請求的數量。稍後在代碼中，您將將其附加到qrtList。

Answer 2

使用qty：

calories = int(conv(carbs, "c") + conv(fats, "f") + conv(protein, "p") * qty) 

您與qty後填寫您的列表：qtyList.append(qty)使用電流值應工作。