Python 使用 IF ELIF 和 ELSE 語句進行調試

Question

所以我目前正在解決這個調試問題，並且已經卡了幾個小時，所以我想我會試一試。 這是問題所在，我需要編寫代碼，以正確 output 列出所列食品的組合的適當成本。 我知道正確的金額是 6.50 美元，但我一直得到 6.00 美元。

item = "nachos"
meat = "steak"
queso = True
guacamole = False
double_meat = True


#-----------------------------------------------------------
#You may modify the lines of code above, but don't move them!
#When you Submit your code, we'll change these lines to
#assign different values to the variables.
#
#Let's further expand our previous program to cover a broader
#menu variety. Instead of just burritos, now the program
#should cover three menu items: quesadillas, burritos, and
#nachos. Instead of separate booleans for steak and pork,
#we instead have a string that could be "steak", "pork",
#"chicken", "tofu", and "beef". We still have booleans for
#queso and guacamole, but we also have a boolean for double
#meat.
#
#Your code should calculate the price as follows:
#
# - The base price for a quesadilla is 4.00, for nachos is
#   4.50, and for burritos is 5.00.
# - If meat is steak or pork, add 0.50. Any other meat adds
#   no money to the price.
# - guacamole always adds 1.00 to the price.
# - queso adds 1.00 to the price UNLESS the item is nachos,
#   in which case it adds nothing.
# - double_meat adds 1.50 if the meat is steak or pork, or
#   1.00 otherwise.


if item == "quesadilla":
    base_price = 4.0
    if meat == "steak" or meat == "pork":
        base_price += 0.50
    if guacamole:
        base_price += 1.00
    if queso:
        base_price += 1.00
    if double_meat == "steak" or double_meat == "pork":
        base_price += 1.50
    else:
        base_price += 1.00
       
elif item == "nachos":
    base_price = 4.50
    if meat == "steak" or meat == "pork":
        base_price += 0.50   
    if guacamole:
        base_price += 1.00
    if double_meat == "steak" or double_meat == "pork":
        base_price += 1.50
    else:
        base_price += 1.00   

elif item == "burrito":
    base_price = 5.0
    if meat == "steak" or meat == "pork":
        base_price += 0.50
    if guacamole:
        base_price += 1.00
    if queso:
        base_price += 1.00
    if double_meat == "steak" or double_meat == "pork":
        base_price += 1.50
    else:
        base_price += 1.00

print(base_price)

所以，從我收集的內容來看，我的代碼正在跳過

"if double_meat == "steak" or double_meat == "pork":
   
 base_price += 1.50"

部分代碼並直接進入

"else:
    base_price += 1.00"

部分，我似乎無法弄清楚為什么。 任何幫助，將不勝感激。

Answer 1

檢查您正在比較double_meat的數據類型，在這種情況下它不是 boolean，因為您將其設置為上面。

Answer 2

您在這里將值與字符串進行比較； 但是您在上面聲明了它 boolean 。 現在，當您宣布“真實”時，它將起作用

item = "nachos"
meat = "steak"
queso = True
guacamole = False
double_meat = True

if item == "quesadilla":
   base_price = 4.0
   if meat == "steak" or meat == "pork":
       base_price += 0.50
   if guacamole:
       base_price += 1.00
   if queso:
       base_price += 1.00
   if double_meat or double_meat:
       base_price += 1.50
   else:
       base_price += 1.00
      
elif item == "nachos":
   base_price = 4.50
   if meat == "steak" or meat == "pork":
       base_price += 0.50
       
   if guacamole:
       base_price += 1.00
     
   if double_meat or double_meat: #it now validating true/false
       base_price += 1.50
   else:
       base_price += 1.00


elif item == "burrito":
   base_price = 5.0
   if meat == "steak" or meat == "pork":
       base_price += 0.50
   if guacamole:
       base_price += 1.00
   if queso:
       base_price += 1.00
   if double_meat or double_meat:
       base_price += 1.50
   else:
       base_price += 1.00

print(base_price)