Python实现的井字棋（Tic Tac Toe）游戏示例

#作者：hhh5460#时间：2017年6月26日# 棋盘class Board(object): def __init__(self):  #self._board = '-'*9 # 坑！！  self._board = ['-' for _ in range(9)]  self._history = [] # 棋谱 # 按指定动作，放入棋子 def _move(self, action, take):  if self._board[action] == '-':   self._board[action] = take   self._history.append((action, take)) # 加入棋谱 # 撤销动作，拿走棋子 def _unmove(self, action):  self._board[action] = '-'  self._history.pop() # 棋盘快照 def get_board_snapshot(self):  return self._board[:] # 取棋盘上的合法走法 def get_legal_actions(self):  actions = []  for i in range(9):   if self._board[i] == '-':    actions.append(i)  return actions # 判断走法是否合法 def is_legal_action(self, action):  return self._board[action] == '-' # 终止检测 def teminate(self):  board = self._board  lines = [board[0:3], board[3:6], board[6:9], board[0::3], board[1::3], board[2::3], board[0::4], board[2:7:2]]  if ['X']*3 in lines or ['O']*3 in lines or '-' not in board:   return True  else:   return False # 胜负检查 def get_winner(self):  board = self._board  lines = [board[0:3], board[3:6], board[6:9], board[0::3], board[1::3], board[2::3], board[0::4], board[2:7:2]]  if ['X']*3 in lines:   return 0  elif ['O']*3 in lines:   return 1  else:   return 2 # 打印棋盘 def print_b(self):  board = self._board  for i in range(len(board)):   print(board[i], end='')   if (i+1)%3 == 0:    print() # 打印棋谱 def print_history(self):  print(self._history)# 玩家class Player(object): ''' 玩家只做两件事：思考、落子  1. 思考 --> 得到走法  2. 落子 --> 执行走法，改变棋盘 ''' def __init__(self, take='X'): # 默认执的棋子为 take = 'X'  self.take=take def think(self, board):  pass def move(self, board, action):  board._move(action, self.take)# 人类玩家class HumanPlayer(Player): def __init__(self, take):  super().__init__(take) def think(self, board):  while True:   action = input('Please input a num in 0-8:')   if len(action)==1 and action in '012345678' and board.is_legal_action(int(action)):    return int(action)# 电脑玩家class AIPlayer(Player): def __init__(self, take):  super().__init__(take) def think(self, board):  print('AI is thinking ...')  take = ['X','O'][self.take=='X']  player = AIPlayer(take)  # 假想敌！！！  _, action = self.minimax(board, player)  #print('OK')  return action # 极大极小法搜索，α-β剪枝 def minimax(self, board, player, depth=0) :  '''参考：https://stackoverflow.com/questions/44089757/minimax-algorithm-for-tic-tac-toe-python'''  if self.take == "O":   bestVal = -10  else:   bestVal = 10  if board.teminate() :   if board.get_winner() == 0 :    return -10 + depth, None   elif board.get_winner() == 1 :    return 10 - depth, None   elif board.get_winner() == 2 :    return 0, None  for action in board.get_legal_actions() : # 遍历合法走法   board._move(action, self.take)   val, _ = player.minimax(board, self, depth+1) # 切换到 假想敌！！！   board._unmove(action) # 撤销走法，回溯   if self.take == "O" :    if val > bestVal:     bestVal, bestAction = val, action   else :    if val < bestVal:     bestVal, bestAction = val, action  return bestVal, bestAction# 游戏class Game(object): def __init__(self):  self.board = Board()  self.current_player = None # 生成玩家 def mk_player(self, p, take='X'): # p in [0,1]  if p==0:   return HumanPlayer(take)  else:   return AIPlayer(take) # 切换玩家 def switch_player(self, player1, player2):  if self.current_player is None:   return player1  else:   return [player1, player2][self.current_player == player1] # 打印赢家 def print_winner(self, winner): # winner in [0,1,2]  print(['Winner is player1','Winner is player2','Draw'][winner]) # 运行游戏 def run(self):  ps = input("Please select two player's type:/n/t0.Human/n/t1.AI/nSuch as:0 0/n")  p1, p2 = [int(p) for p in ps.split(' ')]  player1, player2 = self.mk_player(p1, 'X'), self.mk_player(p2, 'O') # 先手执X，后手执O  print('/nGame start!/n')  self.board.print_b() # 显示棋盘  while True:   self.current_player = self.switch_player(player1, player2) # 切换当前玩家   action = self.current_player.think(self.board) # 当前玩家对棋盘进行思考后，得到招法   self.current_player.move(self.board, action) # 当前玩家执行招法，改变棋盘   self.board.print_b() # 显示当前棋盘   if self.board.teminate(): # 根据当前棋盘，判断棋局是否终止    winner = self.board.get_winner() # 得到赢家 0,1,2    break  self.print_winner(winner)  print('Game over!')  self.board.print_history()if __name__ == '__main__': Game().run()