用python编写一个字符界面的五子棋人机对战代码，并且规范代码格式

以下是一个简单的五子棋人机对战代码，实现了基本的游戏规则和人机对战的功能。代码规范遵循 PEP 8 标准。

import random

class ChessBoard:
    def __init__(self, size=15):
        self.size = size
        self.board = [['+' for i in range(size)] for j in range(size)]
    
    def display(self):
        print('   ', end='')
        for i in range(self.size):
            print(chr(ord('a')+i), end=' ')
        print()
        for i in range(self.size):
            print('{:>2d}'.format(i+1), end=' ')
            for j in range(self.size):
                print(self.board[i][j], end=' ')
            print()
    
    def put(self, x, y, ch):
        if x < 0 or x >= self.size or y < 0 or y >= self.size:
            return False
        if self.board[x][y] != '+':
            return False
        self.board[x][y] = ch
        return True
    
    def check(self, x, y, ch):
        count = 0
        for i in range(x-4, x+5):
            if i < 0 or i >= self.size:
                continue
            if self.board[i][y] == ch:
                count += 1
                if count >= 5:
                    return True
            else:
                count = 0
        count = 0
        for j in range(y-4, y+5):
            if j < 0 or j >= self.size:
                continue
            if self.board[x][j] == ch:
                count += 1
                if count >= 5:
                    return True
            else:
                count = 0
        count = 0
        for i in range(-4, 5):
            if x+i < 0 or x+i >= self.size or y+i < 0 or y+i >= self.size:
                continue
            if self.board[x+i][y+i] == ch:
                count += 1
                if count >= 5:
                    return True
            else:
                count = 0
        count = 0
        for i in range(-4, 5):
            if x+i < 0 or x+i >= self.size or y-i < 0 or y-i >= self.size:
                continue
            if self.board[x+i][y-i] == ch:
                count += 1
                if count >= 5:
                    return True
            else:
                count = 0
        return False

class ChessGame:
    def __init__(self, size=15):
        self.board = ChessBoard(size)
        self.players = ['X', 'O']
    
    def play(self):
        player = 0
        while True:
            self.board.display()
            print('Player', player+1, 'turn')
            x, y = self.get_input(player)
            if self.board.put(x, y, self.players[player]):
                if self.board.check(x, y, self.players[player]):
                    self.board.display()
                    print('Player', player+1, 'wins!')
                    return
                player = 1 - player
            else:
                print('Invalid move')
    
    def get_input(self, player):
        if player == 0:
            x = int(input('Enter x coordinate: ')) - 1
            y = ord(input('Enter y coordinate: ')) - ord('a')
            return x, y
        else:
            print('Computer is thinking...')
            x, y = self.get_computer_input()
            print('Computer put', chr(ord('a')+y)+str(x+1))
            return x, y
    
    def get_computer_input(self):
        while True:
            x = random.randint(0, self.board.size-1)
            y = random.randint(0, self.board.size-1)
            if self.board.put(x, y, self.players[1]):
                if self.board.check(x, y, self.players[1]):
                    self.board.put(x, y, '+')
                    continue
                return x, y

if __name__ == '__main__':
    game = ChessGame()
    game.play()

代码中使用了 `ChessBoard` 类和 `ChessGame` 类来实现五子棋游戏的逻辑。其中 `ChessBoard` 类用于表示棋局状态和操作，`ChessGame` 类用于控制游戏流程和玩家交互。实现了人机对战功能，计算机玩家使用随机策略来下棋。