Tic-Tac-Toe游戏

 #Tic-Tac-Toe
 #机器人和人类下井字棋

 #全局变量
 import random
 X = "X"
 O = "O"
 EMPTY = " "      #表示棋盘上的空空格
 TIE = "TIE"      #表示平局
 NUM_SQUARES = 9  #井字棋棋盘上的方格数

 #显示游戏说明
 def display_instruct():
     """Display game instrcutin."""
     print(
         """Welcome to the gratest intellectual challenge of all time:Tic-Tac-Toe.
         This will be a showdown between your human brain and my silicon proessor.
         you will make your move known by entering a nmber,0 - 8. The number will
         correspond to the board position as illustrated:
          0 | 1 | 2
          ---------
          3 | 4 | 5
          ---------
          6 | 7 | 8
         Prepare yourself,human .The ultimate battle is about aobegin.\n"""
     )

 #询问一个“是或否”的问题。接受一个问题，返回y或n
 def ask_yes_no(quesion):
     response = None
     while response not in ("y","n"):
         response = input(quesion.lower())
     return response

 #求情指定范围内的一个数字
 def ask_number(question,low,high):
     response = None
     while response not in range(low,high):
         response = int(input(question))
     return response

 #询问玩家是否希望先行棋
 def pieces():
     go_first = ask_yes_no("Do you require the first move ? (y/n):")
     if go_first =="y":
         print "\nThen take the first move.You wil need it."
         human = X
         computer = O
     else:
         print "\nYour bravery will be your undoing... I will go first.."
         human = O
         computer = X
     return computer, human

 #创建新的q棋盘
 def new_board():
     board = []
     for square in range(NUM_SQUARES):
         board.append(EMPTY)
     return board

 #显示棋盘
 def display_board(board):
     print "\n\t",board[0],"|",board[1],"|",board[2]
     print "\t","--------"
     print "\n\t",board[3],"|",board[4],"|",board[5]
     print "\t","--------"
     print "\n\t",board[6],"|",board[7],"|",board[8]

 #接受一个棋盘，返回一个合法的行棋步骤
 def legal_moves(board):
     moves = []
     for square in range(NUM_SQUARES):
         if board[square] == EMPTY:
             moves.append(square)
     return moves

 #判断输赢
 def winner(board):
     WAYS_TO_WIN = ((0,1,2),(3,4,5),(6,7,8),(0,3,6),(1,4,7),(2,5,8),(0,4,8),(2,4,6))
     winner = ""
     for row in WAYS_TO_WIN:
         if board[row[0]] == board[row[1]] == board[row[2]]!=EMPTY:
             winner = board[row[0]]
             return winner
     if winner=="":
         if EMPTY not in board:
              return TIE
         else:
             return None

 #用户行棋
 def human_move(board,human):
     legal = legal_moves(board)
     move = None
     while move not in legal:
         move = ask_number("Where you will move ?(0-8):",0,NUM_SQUARES)
         if move not in legal:
             print ("\nThat square is already occupied,foolish human.Choose another.\n")
     print "Fine..."
     return move

 #机器人行棋
 def computer_move(board,computer,human):
     board = board[:]
     BEST_MOVES =(4,0,2,6,8,1,3,5,7)

     #如果机器人能赢，就走那个位置
     for move in legal_moves(board):
         board[move] = computer
         if winner(board) == computer:
              print move
              return move
         #技术当前行棋方案的测试，并取消之
         board[move] =EMPTY
     #如果玩家能赢，就堵住那个位置
     for move in legal_moves(board):
         board[move] = human
         if winner(board) == human:
              print move
              return move
         #技术当前行棋方案的测试，并取消之
         board[move] =EMPTY

     #由于本轮谁也赢不了，所以叫挑选最佳的空位来走
     for move in BEST_MOVES:
         if move in legal_moves(board):
             print move
             return  move

 #返回下一个行棋方
 def next_turn(turn):
     if turn == X:
         return O
     else:
         return X

 #接受游戏的赢家
 def congract_winner(the_winner,computer,humna):
     if the_winner !=TIE:
         print the_winner,"won"
     else:
         print "tie!"

     if the_winner==computer:
         print "computer win"
     elif the_winner ==humna:
         print "human win!"
     elif the_winner==TIE:
         print "tie"

 #
 def main():
     display_instruct()
     computer,human = pieces()
     turn = X
     board = new_board()
     display_board(board)

     while not winner(board):
         if turn == human:
             move = human_move(board,human)
             board[move] = human
         else:
             move = computer_move(board,computer,human)
             board[move] = computer
         display_board(board)
         turn = next_turn(turn)
     the_winner = winner(board)
     congract_winner(the_winner,computer,human)

 main()

执行过程：

Python 2.7.6 (default, Nov 10 2013, 19:24:24) [MSC v.1500 64 bit (AMD64)] on win32
Type "copyright", "credits" or "license()" for more information.
>>> ================================ RESTART ================================
>>>
Welcome to the gratest intellectual challenge of all time:Tic-Tac-Toe.
        This will be a showdown between your human brain and my silicon proessor.
        you will make your move known by entering a nmber,0 - 8. The number will
        correspond to the board position as illustrated:
         0 | 1 | 2
         ---------
         3 | 4 | 5
         ---------
         6 | 7 | 8
        Prepare yourself,human .The ultimate battle is about aobegin.

do you require the first move ? (y/n):"y"

Then take the first move.You wil need it.

      |   |
    --------

      |   |
    --------

      |   |
Where you will move ?(0-8):4
Fine...

      |   |
    --------

      | X |
    --------

      |   |
0

    O |   |
    --------

      | X |
    --------

      |   |
Where you will move ?(0-8):2
Fine...

    O |   | X
    --------

      | X |
    --------

      |   |
6

    O |   | X
    --------

      | X |
    --------

    O |   |
Where you will move ?(0-8):3
Fine...

    O |   | X
    --------

    X | X |
    --------

    O |   |
5

    O |   | X
    --------

    X | X | O
    --------

    O |   |
Where you will move ?(0-8):1
Fine...

    O | X | X
    --------

    X | X | O
    --------

    O |   |
7

    O | X | X
    --------

    X | X | O
    --------

    O | O |
Where you will move ?(0-8):8
Fine...

    O | X | X
    --------

    X | X | O
    --------

    O | O | X
tie!
tie
>>>