python之2048

 #-*- coding:utf-8 -*-

 import curses
 from random import randrange, choice # generate and place new tile
 from collections import defaultdict

 letter_codes = [ord(ch) for ch in 'WASDRQwasdrq']
 actions = ['Up', 'Left', 'Down', 'Right', 'Restart', 'Exit']
 actions_dict = dict(zip(letter_codes, actions * 2))

 def get_user_action(keyboard):
     char = "N"
     while char not in actions_dict:
         char = keyboard.getch()
     return actions_dict[char]

 def transpose(field):
     return [list(row) for row in zip(*field)]

 def invert(field):
     return [row[::-1] for row in field]

 class GameField(object):
     def __init__(self, height=4, width=4, win=2048):
         self.height = height
         self.width = width
         self.win_value = 2048
         self.score = 0
         self.highscore = 0
         self.reset()

     def reset(self):
         if self.score > self.highscore:
             self.highscore = self.score
         self.score = 0
         self.field = [[0 for i in range(self.width)] for j in range(self.height)]
         self.spawn()
         self.spawn()

     def move(self, direction):
         def move_row_left(row):
             def tighten(row): # squeese non-zero elements together
                 new_row = [i for i in row if i != 0]
                 new_row += [0 for i in range(len(row) - len(new_row))]
                 return new_row

             def merge(row):
                 pair = False
                 new_row = []
                 for i in range(len(row)):
                     if pair:
                         new_row.append(2 * row[i])
                         self.score += 2 * row[i]
                         pair = False
                     else:
                         if i + 1 < len(row) and row[i] == row[i + 1]:
                             pair = True
                             new_row.append(0)
                         else:
                             new_row.append(row[i])
                 assert len(new_row) == len(row)
                 return new_row
             return tighten(merge(tighten(row)))

         moves = {}
         moves['Left']  = lambda field:                              \
                 [move_row_left(row) for row in field]
         moves['Right'] = lambda field:                              \
                 invert(moves['Left'](invert(field)))
         moves['Up']    = lambda field:                              \
                 transpose(moves['Left'](transpose(field)))
         moves['Down']  = lambda field:                              \
                 transpose(moves['Right'](transpose(field)))

         if direction in moves:
             if self.move_is_possible(direction):
                 self.field = moves[direction](self.field)
                 self.spawn()
                 return True
             else:
                 return False

     def is_win(self):
         return any(any(i >= self.win_value for i in row) for row in self.field)

     def is_gameover(self):
         return not any(self.move_is_possible(move) for move in actions)

     def draw(self, screen):
         help_string1 = '(W)Up (S)Down (A)Left (D)Right'
         help_string2 = '     (R)Restart (Q)Exit'
         gameover_string = '           GAME OVER'
         win_string = '          YOU WIN!'
         def cast(string):
             screen.addstr(string + '\n')

         def draw_hor_separator():
             line = '+' + ('+------' * self.width + '+')[1:]
             separator = defaultdict(lambda: line)
             if not hasattr(draw_hor_separator, "counter"):
                 draw_hor_separator.counter = 0
             cast(separator[draw_hor_separator.counter])
             draw_hor_separator.counter += 1

         def draw_row(row):
             cast(''.join('|{: ^5} '.format(num) if num > 0 else '|      ' for num in row) + '|')

         screen.clear()
         cast('SCORE: ' + str(self.score))
         if 0 != self.highscore:
             cast('HGHSCORE: ' + str(self.highscore))
         for row in self.field:
             draw_hor_separator()
             draw_row(row)
         draw_hor_separator()
         if self.is_win():
             cast(win_string)
         else:
             if self.is_gameover():
                 cast(gameover_string)
             else:
                 cast(help_string1)
         cast(help_string2)

     def spawn(self):
         new_element = 4 if randrange(100) > 89 else 2
         (i,j) = choice([(i,j) for i in range(self.width) for j in range(self.height) if self.field[i][j] == 0])
         self.field[i][j] = new_element

     def move_is_possible(self, direction):
         def row_is_left_movable(row):
             def change(i): # true if there'll be change in i-th tile
                 if row[i] == 0 and row[i + 1] != 0: # Move
                     return True
                 if row[i] != 0 and row[i + 1] == row[i]: # Merge
                     return True
                 return False
             return any(change(i) for i in range(len(row) - 1))

         check = {}
         check['Left']  = lambda field:                              \
                 any(row_is_left_movable(row) for row in field)

         check['Right'] = lambda field:                              \
                  check['Left'](invert(field))

         check['Up']    = lambda field:                              \
                 check['Left'](transpose(field))

         check['Down']  = lambda field:                              \
                 check['Right'](transpose(field))

         if direction in check:
             return check[direction](self.field)
         else:
             return False

 def main(stdscr):
     def init():
         #重置游戏棋盘
         game_field.reset()
         return 'Game'

     def not_game(state):
         #画出 GameOver 或者 Win 的界面
         game_field.draw(stdscr)
         #读取用户输入得到action，判断是重启游戏还是结束游戏
         action = get_user_action(stdscr)
         responses = defaultdict(lambda: state) #默认是当前状态，没有行为就会一直在当前界面循环
         responses['Restart'], responses['Exit'] = 'Init', 'Exit' #对应不同的行为转换到不同的状态
         return responses[action]

     def game():
         #画出当前棋盘状态
         game_field.draw(stdscr)
         #读取用户输入得到action
         action = get_user_action(stdscr)

         if action == 'Restart':
             return 'Init'
         if action == 'Exit':
             return 'Exit'
         if game_field.move(action): # move successful
             if game_field.is_win():
                 return 'Win'
             if game_field.is_gameover():
                 return 'Gameover'
         return 'Game'

     state_actions = {
             'Init': init,
             'Win': lambda: not_game('Win'),
             'Gameover': lambda: not_game('Gameover'),
             'Game': game
         }

     curses.use_default_colors()
     game_field = GameField(win=32)

     state = 'Init'

     #状态机开始循环
     while state != 'Exit':
         state = state_actions[state]()

 curses.wrapper(main)