Python返回“無”

Question

我代碼中的其他所有內容均正常運行，但是每次要求將新項目添加到列表中時，python也會返回“ None”，我試圖擺脫這一點，我們將不勝感激。

這是我的代碼：

#Welcome
name = input("What is your name? ")
print("Welcome %s to your shopping list" %name)

#Adding to the list
shoppingList = []
while True:
    new_item = input(print("Please enter an item of your shopping list and type END when you have entered all of your items: "))
    if new_item == "END": break
    shoppingList.append(new_item)
length = len(shoppingList)
print("Your shopping list is", length, "item(s) long.")
shoppingList.sort
print("This is your list: ", shoppingList)

#Prompting the user to change list if necessary
change = input(print("Is there anything you wish to change?"))
if 'No' in change: print("Great.")
else:
    delete = input(print("Which item would you like to replace?"))
    shoppingList.remove(delete)
replace = input(print("What would you like to replace it with?"))
shoppingList.append(replace)
print("This is your new list: ", shoppingList)

Answer 1

您在input() print()內部調用print() ，而print()返回None 。 只需將字符串傳遞給input() ：

input("Is there anything you wish to change?")

另外， shoppingList.sort不會執行任何操作。 您需要正確地調用它： shoppingList.sort() 。