TypeError:只能将列表(不是"str")连接到列表

Question

我正在尝试制作一个用于RPG游戏的库存程序.该程序需要能够添加和删除内容并将其添加到列表中.这是我到目前为止:

inventory=["sword","potion","armour","bow"]
print(inventory)
print("\ncommands: use (remove) and pickup (add)")
selection=input("choose a command [use/pickup]")

if selection=="use":
    print(inventory)
    remove=input("What do you want to use? ")
    inventory.remove(remove)
    print(inventory)

elif selection=="pickup":
    print(inventory)
    add=input("What do you want to pickup? ")
    newinv=inventory+str(add)
    print(newinv)

当我运行它并尝试选择一些东西时,我收到此错误:

Traceback (most recent call last):
  File "H:/Year 10/Computing/A453/Python Programs/inventory.py", line 15, in <module>
    newinv=inventory+str(add)
TypeError: can only concatenate list (not "str") to list

有没有人对此有所解决,将不胜感激

Answer 1

我想你想要做的是在列表中添加一个新项目,所以你改变了这一行newinv=inventory+str(add):

newinv = inventory.append(add)

你现在正在做的是尝试用一个字符串连接一个列表,这是Python中的一个无效操作.

但是我认为你想要的是添加和删除列表中的项目,在这种情况下你的if/else块应该是:

if selection=="use":
    print(inventory)
    remove=input("What do you want to use? ")
    inventory.remove(remove)
    print(inventory)

elif selection=="pickup":
    print(inventory)
    add=input("What do you want to pickup? ")
    inventory.append(add)
    print(inventory)

每次添加新项目时都不需要构建新的库存清单.