用Python写五子棋

很抱歉，我是一个语言模型AI，无法编写实际的代码，但是我可以提供一份五子棋的Python实现代码供你参考：

import os
import sys

# 五子棋类
class Gobang:
    # 初始化
    def __init__(self):
        self.board_size = 15   # 棋盘大小
        self.board = []        # 棋盘
        for i in range(self.board_size):
            self.board.append(["+" for j in range(self.board_size)])
        self.chess = "x"       # 刚开始下棋的颜色
        self.win_flag = False  # 是否已分出胜负

    # 打印棋盘
    def print_board(self):
        os.system("cls")
        print(" " * 2, end="")
        for j in range(self.board_size):
            print(chr(ord("A") + j), end=" ")
        print()
        for i in range(self.board_size):
            print("{:>2} ".format(i + 1), end="")
            for j in range(self.board_size):
                print(self.board[i][j], end=" ")
            print()
        print()

    # 判断棋子是否在范围内
    def is_valid(self, x, y):
        if x < 0 or x >= self.board_size or y < 0 or y >= self.board_size:
            return False
        return True

    # 判断位置是否已经有棋子了
    def is_empty(self, x, y):
        if self.board[x][y] == "+":
            return True
        return False

    # 落子
    def drop_chess(self, x, y):
        self.board[x][y] = self.chess

    # 切换下棋的颜色
    def toggle_chess(self):
        if self.chess == "x":
            self.chess = "o"
        else:
            self.chess = "x"

    # 判断横向是否有五颗相同的棋子
    def check_horizonal(self, x, y):
        count = 1  # 统计相同的棋子数量
        i, j = x, y - 1
        while self.is_valid(i, j) and not self.is_empty(i, j) and self.board[i][j] == self.chess:
            count += 1
            j -= 1
        i, j = x, y + 1
        while self.is_valid(i, j) and not self.is_empty(i, j) and self.board[i][j] == self.chess:
            count += 1
            j += 1
        return count >= 5

    # 判断纵向是否有五颗相同的棋子
    def check_vertical(self, x, y):
        count = 1
        i, j = x - 1, y
        while self.is_valid(i, j) and not self.is_empty(i, j) and self.board[i][j] == self.chess:
            count += 1
            i -= 1
        i, j = x + 1, y
        while self.is_valid(i, j) and not self.is_empty(i, j) and self.board[i][j] == self.chess:
            count += 1
            i += 1
        return count >= 5

    # 判断左上到右下是否有五颗相同的棋子
    def check_diag1(self, x, y):
        count = 1
        i, j = x - 1, y - 1
        while self.is_valid(i, j) and not self.is_empty(i, j) and self.board[i][j] == self.chess:
            count += 1
            i -= 1
            j -= 1
        i, j = x + 1, y + 1
        while self.is_valid(i, j) and not self.is_empty(i, j) and self.board[i][j] == self.chess:
            count += 1
            i += 1
            j += 1
        return count >= 5

    # 判断右上到左下是否有五颗相同的棋子
    def check_diag2(self, x, y):
        count = 1
        i, j = x - 1, y + 1
        while self.is_valid(i, j) and not self.is_empty(i, j) and self.board[i][j] == self.chess:
            count += 1
            i -= 1
            j += 1
        i, j = x + 1, y - 1
        while self.is_valid(i, j) and not self.is_empty(i, j) and self.board[i][j] == self.chess:
            count += 1
            i += 1
            j -= 1
        return count >= 5

    # 判断是否已经分出胜负
    def check_win(self, x, y):
        if (
            self.check_horizonal(x, y)
            or self.check_vertical(x, y)
            or self.check_diag1(x, y)
            or self.check_diag2(x, y)
        ):
            return True
        return False

    # 游戏循环
    def game_loop(self):
        while not self.win_flag:
            self.print_board()
            chess_pos = input("{} to move (e.g. A1): ".format(self.chess)).strip().upper()
            if len(chess_pos) != 2:
                continue
            x = ord(chess_pos[0]) - ord("A")
            y = int(chess_pos[1:]) - 1
            if not self.is_valid(x, y) or not self.is_empty(x, y):
                continue
            self.drop_chess(x, y)
            if self.check_win(x, y):
                self.win_flag = True
                print("{} wins!".format(self.chess))
            self.toggle_chess()

# 主函数
def main():
    gobang = Gobang()
    gobang.game_loop()

if __name__ == "__main__":
    main()

这份代码实现了以下功能：

- 初始化一个15x15的棋盘；
- 下棋的初始颜色是黑色（"x"）；
- 双方轮流输入棋子的位置坐标，可以输入类似于"A1"这样的形式，输入无效的坐标会被忽略；
- 每次落子后会检查是否已经分出胜负，如果已经有一方胜利，则游戏结束。