如何将FEN ID转换为棋盘？

def fen_to_board(fen_id):
    fen_parts = fen_id.split(' ')
    board_state = fen_parts[0]
    board = [[None] * 8 for _ in range(8)]

    row = 0
    col = 0
    for char in board_state:
        if char == '/':
            row += 1
            col = 0
        elif char.isdigit():
            col += int(char)
        else:
            board[row][col] = char
            col += 1

    return board

# 示例用法
fen_id = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR"
chess_board = fen_to_board(fen_id)
for row in chess_board:
    print(row)

['r', 'n', 'b', 'q', 'k', 'b', 'n', 'r']
['p', 'p', 'p', 'p', 'p', 'p', 'p', 'p']
[None, None, None, None, None, None, None, None]
[None, None, None, None, None, None, None, None]
[None, None, None, None, None, None, None, None]
[None, None, None, None, None, None, None, None]
['P', 'P', 'P', 'P', 'P', 'P', 'P', 'P']
['R', 'N', 'B', 'Q', 'K', 'B', 'N', 'R']