请编写一个Python的五子棋小游戏

创建一个基本的五子棋游戏需要实现棋盘的显示、玩家的交替下棋、判断胜负等功能。下面是一个简单的五子棋Python程序示例：

# 五子棋游戏
BOARD_SIZE = 15
EMPTY_MARK = '-'
PLAYER_X = 'X'
PLAYER_O = 'O'

def print_board(board):
    for row in board:
        print(' '.join(row))

def is_valid_move(board, row, col):
    return 0 <= row < BOARD_SIZE and 0 <= col < BOARD_SIZE and board[row][col] == EMPTY_MARK

def make_move(board, row, col, player):
    board[row][col] = player

def is_winner(board, player):
    directions = [(0, 1), (1, 0), (1, 1), (1, -1)]
    for row in range(BOARD_SIZE):
        for col in range(BOARD_SIZE):
            if board[row][col] == player:
                for direction in directions:
                    win = True
                    for n in range(1, 5):
                        r = row + direction[0] * n
                        c = col + direction[1] * n
                        if r < 0 or r >= BOARD_SIZE or c < 0 or c >= BOARD_SIZE or board[r][c] != player:
                            win = False
                            break
                    if win:
                        return True
    return False

def play_game():
    board = [[EMPTY_MARK] * BOARD_SIZE for _ in range(BOARD_SIZE)]
    current_player = PLAYER_X
    move_count = 0
    while True:
        print_board(board)
        print(f"Player {current_player}'s turn.")
        row = int(input('Enter row: '))
        col = int(input('Enter column: '))
        if is_valid_move(board, row, col):
            make_move(board, row, col, current_player)
            move_count += 1
            if is_winner(board, current_player):
                print_board(board)
                print(f"Player {current_player} wins!")
                break
            if move_count == BOARD_SIZE * BOARD_SIZE:
                print("It's a tie!")
                break
            current_player = PLAYER_O if current_player == PLAYER_X else PLAYER_X
        else:
            print("Invalid move. Try again.")

if __name__ == "__main__":
    play_game()

这段代码实现了一个文本界面的五子棋游戏，玩家通过输入行和列的坐标来下棋。游戏会检查每次落子后是否有玩家获胜。如果棋盘填满且没有玩家获胜，则判定为平局。