用戶輸入選擇后如何重復程序

Question

我正在嘗試創建一個基於文本的購買系統，作為學校的作業。 我需要幫助，以便用戶可以選擇“甜甜圈”（菜單選項之一）后“批量購買”，這將帶回這些選項或告訴用戶說出關鍵字並停止。

這是應該如何進行的示例：

Welcome, to Dino's International Doughnut Shoppe!           
    Please enter your name to begin: Andrew

    Please select a doughnut from the following menu:
    1. Chocolate-dipped Maple Puff ($3.50 each)
    2. Strawberry Twizzler ($2.25 each)
    3. Vanilla Chai Strudel ($4.05 each)
    4. Honey-drizzled Lemon Dutchie ($1.99)
    5. No more doughnuts.
    > 7
    I'm sorry, that's not a valid selection. Please enter a selection from 1-5.

    Please select a doughnut from the following menu:
    1. Chocolate-dipped Maple Puff ($3.50 each)
    2. Strawberry Twizzler ($2.25 each)
    3. Vanilla Chai Strudel ($4.05 each)
    4. Honey-drizzled Lemon Dutchie ($1.99)
    5. No more doughnuts.
    > 1

    How many Chocolate-dipped Maple Puffs would you like to purchase? 12

    Please select a doughnut from the following menu:
    1. Chocolate-dipped Maple Puff ($3.50 each)
    2. Strawberry Twizzler ($2.25 each)
    3. Vanilla Chai Strudel ($4.05 each)
    4. Honey-drizzled Lemon Dutchie ($1.99)
    5. No more doughnuts.
    > 4

    How many Honey-drizzled Lemon Dutchies would you like to purchase? 8

    Please select a doughnut from the following menu:
    1. Chocolate-dipped Maple Puff ($3.50 each)
    2. Strawberry Twizzler ($2.25 each)
    3. Vanilla Chai Strudel ($4.05 each)
    4. Honey-drizzled Lemon Dutchie ($1.99)
    5. No more doughnuts.
    > 4

    How many Honey-drizzled Lemon Dutchies would you like to purchase? 3

    Please select a doughnut from the following menu:
    1. Chocolate-dipped Maple Puff ($3.50 each)
    2. Strawberry Twizzler ($2.25 each)
    3. Vanilla Chai Strudel ($4.05 each)
    4. Honey-drizzled Lemon Dutchie ($1.99)
    5. No more doughnuts.
    > 5

    Andrew, here is your receipt:
    -------------------------------------
    12 Chocolate-dipped Maple Puffs
    3 Honey-drizzled Lemon Dutchies
    -------------------------------------
    Total cost: $47.97

Thank you, have a nice day!

這是我的密碼

print("Welcome to Dino's International Doughnut Shoppe!")
name = input("Please enter your name to begin: ")


choice = 0
while choice not in [1,2,3,4]:
    print("Please enter a valid choice from 1-4.")
    print("Please select a doughnut from the following menu: ")
    print("1. Chocolate-dipped Maple Puff ($3.50 each)")
    print("2. Strawberry Twizzler ($2.25 each)")
    print("3. Vanilla Chai Strudel ($4.05 each)")
    print("4. Honey-drizzled Lemon Dutchie ($1.99)")
    print("5. No more doughnuts.")
    choice = int(input(">"))


if choice == 1:
    chocolate = int(input("How many chocolate-dipped Maple Puff(s) would you like to purchase? "))
elif choice == 2:
    strawberry = int(input("How many Strawberry Twizzler(s) would you like to purchase? "))
elif choice == 3:
    vanilla = int(input("How many Vanilla Chai Strudel(s) would you like to purchase? "))
elif choice == 4:
    honey = int(input("How many Honey-drizzled Lemon Dutchie(s) would you like to purchase? "))

print(f"{name}, Here is your receipt: ")

if choice == 1:
    print("==========================================")
    print(f"{chocolate} Chocolate Dipped Maple Puffs")
    print("==========================================")
    print(f"Total Cost: ${chocolate*3.50:.2f}")
elif choice == 2:
    print("==========================================")
    print(f"{strawberry} Strawberry Twizzlers")
    print("==========================================")
    print(f"Total Cost: ${strawberry*2.25:.2f}")
elif choice == 3:
    print("==========================================")
    print(f"{vanilla} Vanilla Chai Strudels")
    print("==========================================")
    print(f"Total Cost: ${vanilla*4.05:.2f}")
elif choice == 4:
    print("==========================================")
    print(f"{honey} Honey-drizzled Lemon Dutchies")
    print("==========================================")
    print(f"Total Cost: ${honey*1.99:.2f}")

print("Thank you for shopping at Dino's International Doughnut Shoppe! Please come again!")

Answer 1

我可以建議這個代碼框架嗎？

...
while True:   # i.e., loop  F O R E V E R
   reply = present_menu()
   if not (1 <= reply <= 5) :
       show_error_message()
       continue # i.e., abort this cycle and start a new loop cycle
   if reply == 5:
       recapitulation()
       break # i.e., exit the forever loop
   how_many = ask_how_many(reply)
   update_purchases(reply, how_many)
...

真正重要的是以下想法

• 無限循環
• 如果答案不令人滿意，請使用continue語句中止並開始新的迭代（即再次顯示菜單）
• 如果用戶選擇停止交互，則使用break語句最終退出循環。

您可以根據這些原則將所有代碼放入循環中，也可以按照我的建議， 將重復的代碼段抽象為輔助函數。

Answer 2

由於這是一個家庭作業問題，因此我不想提供代碼。 但是，我要說的是，您應該考慮將所有代碼放入while循環中，並將其終止條件更改為5。（即，在“ choice == 5”時退出）然后您可以處理選擇和無效選擇的邏輯循環，在一系列if-else中說。