Tic Tac Toe脚本在VSCode运行报IndexError问题求助

问题描述 #

根据Udemy课程编写了简易Tic Tac Toe（井字棋）游戏，该程序在Jupyter Notebook中可正常运行，但在VSCode中执行脚本时出现索引越界错误，需修复指导。

错误信息 #

Traceback (most recent call last):
  File "x:\Python\Python_Bootcamp\Complete-Python-3-Bootcamp-master\04-Milestone Project - 1\TIC_TAC_TOE.py", line 105, in <module>   
    display_board(board)
  File "x:\Python\Python_Bootcamp\Complete-Python-3-Bootcamp-master\04-Milestone Project - 1\TIC_TAC_TOE.py", line 8, in display_board
    print(board[1] + '|' + board[2] + '|' + board[3])
          ~~~~~^^^
IndexError: list index out of range

原代码 #

import random

def display_board(board):
    # print('\n'*100) # Lets you only see one version of the board
    print(board[1] + '|' + board[2] + '|' + board[3])
    print('-----')
    print(board[4] + '|' + board[5] + '|' + board[6])
    print('-----')
    print(board[7] + '|' + board[8] + '|' + board[9])

def player_input():
    marker = ''

    while marker != 'X' and marker != 'O':
        marker = input('Player 1 choose X or O: ')
        
        player1 = marker.upper()

        if player1 == 'X':
            player2 = 'O'
        else:
            player2 = 'X'

    return(player1, player2)

def place_marker(board,marker,position):
    board[position] = marker

def win_check(board, mark):
    return ((board[7] == mark and board[8] == mark and board[9] == mark) or # across the bottom
    (board[4] == mark and board[5] == mark and board[6] == mark) or # across the middle
    (board[1] == mark and board[2] == mark and board[3] == mark) or # across the top
    (board[7] == mark and board[4] == mark and board[1] == mark) or # down the left column
    (board[2] == mark and board[5] == mark and board[8] == mark) or # down the middle
    (board[3] == mark and board[6] == mark and board[9] == mark) or # down the right side
    (board[3] == mark and board[5] == mark and board[7] == mark) or # diagonal
    (board[9] == mark and board[5] == mark and board[1] == mark)) # diagonal

def choose_first():
    flip = random.randint(0,1)

    if flip == 0:
        return ('Player 1')
    else:
        return ('Player 2')

def space_check(board, position):
    return board[position] == ' ' # If space is empty the return value will be True

def full_board_check(board):
    for i in range(1,10):
        if space_check(board,i):
            return False # False meaning the space is empty of marker
        else:
            return True # True meaning the board is full

def player_choice(board):
    position = 0

    while position not in [1,2,3,4,5,6,7,8,9]:
        position = int(input('Choose your position: '))

    return position

def replay():
    
    choice = input('Do you want to play again?')

    return choice == 'Yes'

# GAME SETUP
print('Welcome to Tic Tac Toe!')

while True:
    board = [' '*10]
    player1_marker,player2_marker = player_input()
    turn = choose_first()
    print(turn + ' will go first')
    game_on = ''
    
    play_game = input('Are you ready to play Yes or No?: ')

    if play_game.lower()[0] == 'y':
        game_on == True
    else:
        game_on == False

        # Player 1 Turn
    if turn == 'Player 1':

        # Show board

        display_board(board)

        # Choose a position

        position = player_choice(board)

        # Place marker on chosen position

        place_marker(board,player1_marker,position)

        # Check if they won

        if win_check(board,player1_marker) == True:
            display_board(board)
            print('Player 1 has won the game!')
            game_on = False

        # Check to see if Tie
        else: 
            if full_board_check(board):
                display_board(board)
                print('TIE GAME')
                break

    # If there's no tie turn to Player 2        
    else:
        turn = 'Player 2'

        # Player2's turn.
    if turn == 'Player 2':

        # Show board
        # display_board(board)

        # Show position
        position = player_choice(board)

        #Place marker on position
        place_marker(board,player2_marker,position)

        # Check to see if win
        if win_check(board,player2_marker) == True:
            display_board(board)
            print('Player 2 has won the game!')
            game_on = False
        
        # Check to see if Tie
        else:
            full_board_check(board)
            display_board(board)
            print('TIE GAME')
            break
    else:
        turn = 'Player 1'
    
    # If players do not want to play again, quit
    if not replay():
        break

修复方案 #

1. 修复棋盘初始化错误 #

原代码board = [' '*10]创建了仅包含1个元素的列表（该元素是10个空格的字符串），导致索引1-9不存在，直接引发IndexError。
修复后代码：

board = [' '] * 10

此代码创建包含10个独立空格元素的列表，索引0闲置不用，1-9对应棋盘的9个位置。

2. 修复赋值运算符错误 #

原代码中game_on == True和game_on == False使用了比较运算符==，实际应为赋值运算符=，否则game_on始终为空字符串，游戏逻辑无法正常触发。
修复后代码：

if play_game.lower()[0] == 'y':
    game_on = True
else:
    game_on = False

3. 修复full_board_check函数逻辑错误 #

原函数仅检查第一个位置（i=1）就返回结果，无法正确判断整个棋盘是否填满。需遍历所有位置，确认无空位置后才返回True。
修复后代码：

def full_board_check(board):
    for i in range(1,10):
        if space_check(board,i):
            return False  # 存在空位置，返回False
    return True  # 所有位置都被占用，返回True

4. 修复主游戏循环结构错误 #

原代码仅执行一次玩家回合就终止，未实现持续游戏直到分出胜负或平局。需将玩家回合逻辑放入while game_on:循环中，确保游戏流程正常推进。
修复后主循环代码：

print('Welcome to Tic Tac Toe!')

while True:
    board = [' '] * 10
    player1_marker,player2_marker = player_input()
    turn = choose_first()
    print(turn + ' will go first')
    game_on = False
    
    play_game = input('Are you ready to play Yes or No?: ')

    if play_game.lower()[0] == 'y':
        game_on = True
    else:
        game_on = False

    while game_on:
        # Player 1 Turn
        if turn == 'Player 1':
            # Show board
            display_board(board)
            # Choose a position
            position = player_choice(board)
            # Place marker on chosen position
            place_marker(board,player1_marker,position)
            # Check if they won
            if win_check(board,player1_marker):
                display_board(board)
                print('Player 1 has won the game!')
                game_on = False
            else:
                # Check to see if Tie
                if full_board_check(board):
                    display_board(board)
                    print('TIE GAME')
                    game_on = False
                else:
                    turn = 'Player 2'
        # Player2's turn.
        else:
            # Show board
            display_board(board)
            # Choose position
            position = player_choice(board)
            # Place marker on position
            place_marker(board,player2_marker,position)
            # Check to see if win
            if win_check(board,player2_marker):
                display_board(board)
                print('Player 2 has won the game!')
                game_on = False
            else:
                # Check to see if Tie
                if full_board_check(board):
                    display_board(board)
                    print('TIE GAME')
                    game_on = False
                else:
                    turn = 'Player 1'
    
    # If players do not want to play again, quit
    if not replay():
        break

5. 修复player_choice函数缺失位置可用性检查 #

原函数仅验证输入是否为1-9，但未检查位置是否已被占用，导致玩家可重复选择已被占据的位置。
修复后代码：

def player_choice(board):
    position = 0
    while position not in [1,2,3,4,5,6,7,8,9] or not space_check(board, position):
        position = int(input('Choose your position (1-9): '))
    return position

6. 修复replay函数大小写不兼容问题 #

原函数仅判断输入为严格的'Yes'，导致用户输入小写'yes'时会直接退出游戏，优化后支持大小写无关的判断。
修复后代码：

def replay():
    choice = input('Do you want to play again? (Yes/No): ')
    return choice.lower() == 'yes'

内容的提问来源于stack exchange，提问作者TheLemonPeppaSteppa