插入错误消息时，列表索引超出范围

Question

我希望this was wrong try again!在输入值不在板上时打印，但是不知怎么的，当我选择板外的值时，代码会中断，而不是显示打印的消息

    def legalMove(self):
            if self.board[startX][startY] != False:


    def playerMove(self,tile): 
                if self.legalMove(tile, x, y) == False:
                    continue
                else:
                    break
            else:
                print('this was wrong try again!.')
        return [x, y]

错误

if self.board[startX][startY] != ' ' or not self.isOnBoard(startX, startY): IndexError: list index out of range

Answer 1

您应该交换条件中的语句，这样您就不会出现这样的错误：

def legalMove(self,tile,isOnBoard,startX, startY):
    # swap the statements
    if not self.isOnBoard(startX, startY) or self.board[startX][startY] != ' ':
        print('this was wrong try again!')
        return False
    return True

尽管我建议你在playerMove方法中进行打印，这样你就可以重用legalMove方法，例如如果你以后要构建一个AI播放器的话

def isOnBoard(self, x, y):
    return 0 <= x < 8 and 0 <= y < 8


def legalMove(self, startX, startY): # remove arguments
    return self.isOnBoard(startX, startY) and self.board[startX][startY] != ' '


def playerMove(self,tile): 
    validMove = '0 1 2 3 4 5 6 7'.split()
    while True:
        move = input().lower()
        if len(move) == 2 and move[0] in validMove and move[1] in validMove:
            x = int(move[0])
            y = int(move[1])
            if not self.legalMove(x, y):
                print('this was wrong try again!')
                continue
            else:
                break
        else:
            print('this was wrong try again!.')
    return [x, y]

此外，Python允许将比较链接在一起，比如0 <= x < 8，这更为优雅

最后，虽然我可能错了，但我认为有效的移动应该只在0到7（包括在内）之间。所以validMove = '0 1 2 3 4 5 6 7'.split()