不使用库，设计一个python五子棋代码

以下是一个简单的五子棋代码示例，主要使用了Python的基础语法：

# 定义棋盘大小
BOARD_SIZE = 15

# 定义棋盘
board = [[0] * BOARD_SIZE for _ in range(BOARD_SIZE)]

# 定义落子函数
def play(x, y, player):
    if board[x][y] == 0:
        board[x][y] = player
        return True
    return False

# 定义判断胜负函数
def is_win(player):
    # 判断行
    for i in range(BOARD_SIZE):
        if all(board[i][j] == player for j in range(BOARD_SIZE)):
            return True
    # 判断列
    for j in range(BOARD_SIZE):
        if all(board[i][j] == player for i in range(BOARD_SIZE)):
            return True
    # 判断对角线
    if all(board[i][i] == player for i in range(BOARD_SIZE)):
        return True
    if all(board[i][BOARD_SIZE - i - 1] == player for i in range(BOARD_SIZE)):
        return True
    return False

# 定义主函数
def main():
    player = 1
    while True:
        # 打印棋盘
        for row in board:
            print(row)
        # 输入坐标
        x, y = map(int, input("Player %d's turn. Enter x, y: " % player).split())
        # 落子
        if play(x, y, player):
            # 判断胜负
            if is_win(player):
                print("Player %d wins!" % player)
                return
            # 切换玩家
            player = 3 - player
        else:
            print("Invalid move, try again.")
        
if __name__ == '__main__':
    main()

该代码实现了基本的五子棋规则，包括棋盘大小、落子、判断胜负等功能。运行代码后，会要求两名玩家交替输入落子坐标。当一方获胜时，会打印出胜利者的信息并结束游戏。