python - 当我尝试接受用户输入时，我不断收到以下错误 - ValueError : invalid literal for int() with base 10: ''

Question

这个问题已经有答案了:

ValueError: invalid literal for int() with base 10: '' (16 个回答)

已关闭 4 年前。

我正在尝试创建一个井字游戏，用户在数字键盘上输入 1 - 9。当用户输入一个数字时，它会检查列表中相应的位置是否用空格(“”)表示，如果没有，则会用 X 替换列表中的该位置。

但是，当用户提供的输入只是按下 Enter 键时，我不断收到以下错误: 如果 update_board[int(user_input)] == "": ValueError:以 10 为基数的 int() 的文字无效:''

我提供了上下文代码的信息，但是如何检查用户输入是否只是按回车键？我试图检查 user_input == ""是否有效，但这也不起作用。我遇到了同样的错误。

update_board = ["#"," "," "," "," "," "," "," "," "," "]

def player_turn():
    # Take in player's input so it can be added to the display board.
    user_input = input('Choose your position: ')

    if update_board[int(user_input)] == " ":
        valid_input = True
    else:
        valid_input = False

    while not valid_input:
        user_input = input("That is not an option, please try again.\n> ")
        if update_board[int(user_input)] == " ":
             valid_input = True
        else:
             valid_input = False  

    return int(user_input)

player1 = "X"
update_board[(player_turn())] = player1

Answer 1

如果用户没有输入有效的整数，int(user_input) 将引发此错误。这里的解决方案是提前检查 user_input 值或更简单地使用 try/except block

def get_int(msg):
   while True:
      user_input = input(msg).strip() # get rid of possible whitespaces
      try:
          return int(user_input)
      except ValueError:
          print("Sorry, '{}' is not a valid integer")


def player_turn():
    while True:
        user_input = get_int('Choose your position: ')
        if update_board[user_input] == " ":
            return user_input

        print("That is not an option, please try again.")