如何在def函数内打印

Question

我有一个程序：

games = ['tlou', 'hitman', 'rainbow 6', 'nba2k']
print(games)
def list_o_matic(inp):
    if inp == "":
        games.pop()
        return "the game" + inp + "was deleted"
    elif inp in games:
        games.remove(inp)
        return "the game" + inp + "was removed"
    elif inp != games:
        games.append(inp)
        return "the game" + inp + "was added"
while True:
    if not games:
        print("goodbye!")
        break
    else:
        inp = input("write the name of the game: ")
        if inp == 'quit':
            print("goodbye!")
            break
        else:
            list_o_matic(inp)
            print(games)

它的作用是你写一个名字（这里是一个视频游戏的名字），然后检查它是否在列表中，如果不在列表中，它会添加它，如果是这样的话，程序会删除它。 问题是输出没有函数中的消息，我不知道为什么。在

Answer 1

您可以在代码print(list_o_matic(inp))中进行修改，因为您的函数已经返回了一个字符串。在

Answer 2

由于您是从list_o_matic返回消息，所以您应该只打印来自调用方的返回值：

games = ['tlou', 'hitman', 'rainbow 6', 'nba2k']
print(games)
def list_o_matic(inp):
    if inp == "":
        games.pop()
        return "the game " + inp + " was deleted"
    elif inp in games:
        games.remove(inp)
        return "the game " + inp + " was removed"
    elif inp != games:
        games.append(inp)
        return "the game " + inp + " was added"
while True:
    if not games:
        print("goodbye!")
        break
    else:
        inp = input("write the name of the game: ")
        if inp == 'quit':
            print("goodbye!")
            break
        else:
            print(list_o_matic(inp))
            print(games)

或者，如果您希望按标题所示在函数内打印消息，则打印消息时不返回：

^{pr2}$