Python 如何将输入添加到空列表并保存它？

我正在尝试为游戏中的项目制作一个列表，我必须在我的程序中多次调用它。我注意到输入并没有存储在我的列表中，它每次都会替换它

我使用了

playeritems.append（）

和

playeritems.extend（）

，但它不起作用

def addbackpack():
    global playeritems
    gameitems= ["sword", "potion"]
    playeritems = []
    print ("\nWhat would you like to add to your backpack? The sword or potion?\n")
    p1_additem = str(input())
    if p1_additem in gameitems:
        playeritems.append(p1_additem)
        print ("\nYou added",p1_additem,"to your backpack.\n")
    else:
        print ("\nThat is not a choice!\n")
        return addbackpack()

addbackpack()
print (playeritems)
addbackpack()
print (playeritems)

这是我第一次输入剑，第二次输入药剂后的准确结果：

What would you like to add to your backpack? The sword or potion?

sword

You added sword to your backpack

['sword']

What would you like to add to your backpack? The sword or potion?

potion

You added potion to your backpack

['potion'] 

• 每次进行函数调用时，您都在重新初始化playeritems。相反，只需将列表传递给函数调用

PS：我建议不要使用递归。相反，你可以用这种迭代的方式

def addbackpack():
    gameitems= ["sword", "potion"]
    print ("\nWhat would you like to add to your backpack? The sword or potion?\n")
    p1_additem = str(input())
    # read until player input correct item.
    while p1_additem not in gameitems:
      print ("\nThat is not a choice!\n")
      p1_additem = str(input())
    playeritems.append(p1_additem)
    print ("\nYou added",p1_additem,"to your backpack.\n")

playeritems = []
addbackpack()
print (playeritems)
addbackpack()
print (playeritems)

---

它确实起作用（因为每个新项都会被添加），但是每次调用

addbackack

都会重新初始化

playeritems

，删除之前的所有内容。

不要使用递归调用，只需在函数中使用循环，然后返回列表。每次调用

addbackack（）

时，都会重置

playeritems

的值。您需要将

playeritems

的当前值传递给

addbackack（playeritems）

，以保留当前项目和新项目。@Jean Françoisfare谢谢，我还编写了迭代方法供考虑。

def addbackpack():
    gameitems= ["sword", "potion"]
    print ("\nWhat would you like to add to your backpack? The sword or potion?\n")
    p1_additem = str(input())
    # read until player input correct item.
    while p1_additem not in gameitems:
      print ("\nThat is not a choice!\n")
      p1_additem = str(input())
    playeritems.append(p1_additem)
    print ("\nYou added",p1_additem,"to your backpack.\n")

playeritems = []
addbackpack()
print (playeritems)
addbackpack()
print (playeritems)