Python 仅返回函数中第一次工作的时间

当我用python运行我的石头剪刀游戏，并故意将

'rock'

、

'paper'

或

'scissors'

中的一个拼写错误时，正如预期的那样，它会再次运行

Player_num

函数。但是，当我输入拼写正确的选项时，它将返回数字，并将其作为

NoneType

返回；然而，如果我第一次拼写正确，它将变量号返回为

int

而不是

NoneType

我不知道如何解决这个问题，我已经尝试过跟踪变量，但我没有运气

#Part of rock paper scissors game
def Player_num():
    #Player chooses one of rock paper or scissors
    print("Choose 'rock', 'paper', or 'scissors' by typing that word. ")
    guess = input()
    #The if statement is to decide whether the user's input is right or not
    if Valid_guess(guess):
        #if it is right, it continues with the game
        #the user's choice will be converted to a number 1,2 or 3
        if guess == 'rock':
            number = 1
        elif guess == 'paper':
            number = 2
        elif guess == 'scissors':
            number = 3
        return number
        #if the input is invalid, the system prompts the user to try it again
    else:
        print('That response is invalid.')
        Player_num()

#Part of rock paper scissors game
def Valid_guess(guess):
    #Validates the user's input
    if guess == 'rock' or guess == 'paper' or guess == 'scissors':
        status = True
    else:
        status = False
    #Returns the boolean value status
    return status

---

在函数结束时，在

else

块中，您已写入：

Player_num()

我想你的意思是：

return Player_num()

---

否则，您将获得正确的输入，但不要将其返回给调用者。相反，该函数从末尾运行，并返回默认返回值

None

。

尝试使用以下方法：

def Player_num():
    print("Choose 'rock', 'paper', or 'scissors' by typing that word. ")
    guess = input()
    if Valid_guess(guess):
        if guess == 'rock':
            number = 1
        elif guess == 'paper':
            number = 2
        elif guess == 'scissors':
            number = 3
        return number
    else:
        print('That response is invalid.')
        return Player_num()

def Valid_guess(guess):
    if guess in ['rock', 'paper', 'scissors']:
        return True
    return False

---

Valid\u guess

也被简化为一条语句。

在{'rock'、'paper'、'scissors'中返回guess

将完成所有代码在函数中所做的工作，您还应该使用while循环，而不是继续调用函数如果您要改进代码，最好只返回，

返回guess in{'rock'、'paper'、'剪刀'}

并使用while循环