Python文本象棋项目二维数组异常：放置棋子后整行被填充

我正在开发基于Python的文本象棋项目，已在控制台实现了外观良好的棋盘，但每当尝试放置棋子时，整行都会被填充。原本期望在数组的E4位置放置白兵字符，但结果整行都被填充。

所用代码如下：

import os
global arrowKey
global speed
newchar = ''
arrowKey = {'\x1b[A': 'up'}
class Pieces:
    Black_rook = '♜'
    Black_knight = '♞'
    Black_bishop = '♝'
    Black_queen = '♛'
    Black_king = '♚'
    Black_pawn = '♟︎'
    White_rook = '♖'
    White_knight = '♘'
    White_bishop = '♗'
    White_queen = '♕'
    White_king = '♔'
    White_pawn = '♙'
class Array:
    def __init__(self, x=16, y=8, board=None):
        self.pos = ()
        self.x = x
        self.y = y
        grid = [' ' + '_' * self.x]
        for _ in range(y):
            row = ['|']
            for _ in range(x):
                row.append(' ')
            row.append('|')
            grid.append(row)
        grid.append(' ' + '‾' * self.x)
        self.grid = grid
        if board != None:
            self.grid = board
    def reload(self, say=None):
        os.system('clear')
        if say != None:
            print(say)
        p = ''
        for i in self.grid:
            p = p + ''.join([x for x in i]) + '\n'
        print(p)
    def insert(self, char, x, y):
        self.pos = (x, y)
        self.grid[y][x] = char
    def move(self, direction, char):
        poslist = []
        for y, i in enumerate(self.grid):
            for x, j in enumerate(i):
                if j == char:
                    poslist.append((x, y))
        count = 0
        for posx, posy in poslist:
            if direction == 'down':
                if self.grid[posy + 1][posx] != '‾':
                    self.insert(' ', posx, posy)
                    self.insert(char, posx, posy + 1)
                    self.pos = (posx, posy + 1)
            if direction == 'up':
                if self.grid[posy - 1][posx] != '_':
                    self.insert(' ', posx, posy)
                    self.insert(char, posx, posy - 1)
                    self.pos = (posx, posy - 1)
            if direction == 'left':
                if self.grid[posy][posx - 1] != '|':
                    self.insert(' ', posx, posy)
                    self.insert(char, posx - 1, posy)
                    self.pos = (posx - 1, posy)
            if direction == 'right':
                if self.grid[posy][posx + 1] != '|':
                    self.insert(' ', posx, posy)
                    self.insert(char, posx + 1, posy)
                    self.pos = (posx + 1, posy)
            count += 1
    def getpos(self, char):
        poslist = []
        for y, i in enumerate(self.grid):
            for x, j in enumerate(i):
                if j == char:
                    poslist.append((x, y))
        return poslist
class Chess(Array):
    def __init__(self):
        row = list(''.join(['.' for i in range(8)]))
        board = [row for i in range(8)]
        super().__init__(board=board)
    def reload(self):
        p = ''
        nums = [i + 1 for i in range(8)]
        nums.reverse()
        for x, i in enumerate(self.grid):
            i = [f'{z} ' for z in i]
            p += f'{nums[x]}  {""".join(i)}\n'
        add = [i + ' ' for i in list('ABCDEFG')]
        add.append('H')
        p += '   ' + ''.join(add) + '\n'
        print(p)
    def move(self, move:str):
        move = move.split(' ')
    def placepiece(self, piece, pos):
        pos = list(pos)
        ykey = [i for i in range(8)]
        ykey.reverse()
        x = [x for x, i in enumerate('ABCDEF') if i == pos[0]][0]
        y = ykey[int(pos[1]) - 1]
        x = int(x)
        return x, y
board = Chess()
x, y = board.placepiece(Pieces.White_pawn, 'E4')
board.grid[y][x] = Pieces.White_pawn
print(board.grid)
board.reload()

问题原因 #

Chess类的__init__方法中，创建棋盘数组时犯了Python列表引用的常见错误：

row = list(''.join(['.' for i in range(8)]))
board = [row for i in range(8)]

这里的board由8个指向同一个row列表的元素组成，所有行本质是同一个列表的引用。修改任意一行的元素时，所有行对应位置都会同步改变，这就导致了整行被填充的现象。

另外，placepiece方法中枚举列坐标时只写到F列（enumerate('ABCDEF')），缺少G、H列，会导致放置这两列棋子时出现索引错误。

修复方案 #

1. 修正棋盘数组创建逻辑，确保每一行都是独立列表：

class Chess(Array):
    def __init__(self):
        # 每次循环生成新的row列表，避免引用复用
        board = [list('.' * 8) for _ in range(8)]
        super().__init__(board=board)

2. 补全placepiece方法的列枚举范围：

def placepiece(self, piece, pos):
    pos = list(pos)
    ykey = [i for i in range(8)]
    ykey.reverse()
    # 补充G、H列的枚举
    x = [x for x, i in enumerate('ABCDEFGH') if i == pos[0]][0]
    y = ykey[int(pos[1]) - 1]
    x = int(x)
    return x, y

修改后运行代码，即可正常在E4位置放置单个白兵，不会出现整行填充的问题。

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