https://qiita.com/masa_ramen/items/ac31db0d20ad88cff09a#comment-e7e51a18dc79af5616a6

game2048.py

import random

SIZE = 4
DIGITS = 4


class Game:

    def __init__(self, board=None, verbose=True):
        self.board = [row[:] for row in board or [[0] * SIZE] * SIZE]
        self.verbose = verbose
        self.score = 0

    def show(self):
        separator = ' -' + '-' * (DIGITS + len(' | ')) * SIZE
        print(separator)
        for row in self.board:
            print(' | ' + ' | '.join(f'{tile:{DIGITS}}' for tile in row) + ' |')
        print(separator)

    def scoring(self, tile):
        self.score += tile * 2
        if self.verbose:
            print(f'{tile}+{tile}={tile*2}')

    def move_left(self):
        moved = False
        for row in self.board:
            for left in range(SIZE - 1):
                for right in range(left + 1, SIZE):
                    if row[right] == 0:
                        continue
                    if row[left] == 0:
                        row[left] = row[right]
                        row[right] = 0
                        moved = True
                        continue
                    if row[left] == row[right]:
                        self.scoring(row[right])
                        row[left] += row[right]
                        row[right] = 0
                        moved = True
                        break
                    if row[left] != row[right]:
                        break
        return moved

    def rotate_left(self):
        self.board = [list(row) for row in zip(*self.board)][::-1]

    def rotate_right(self):
        self.board = [list(row)[::-1] for row in zip(*self.board)]

    def rotate_turn(self):
        self.board = [row[::-1] for row in self.board][::-1]

    def flick_left(self):
        moved = self.move_left()
        return moved

    def flick_right(self):
        self.rotate_turn()
        moved = self.move_left()
        self.rotate_turn()
        return moved

    def flick_up(self):
        self.rotate_left()
        moved = self.move_left()
        self.rotate_right()
        return moved

    def flick_down(self):
        self.rotate_right()
        moved = self.move_left()
        self.rotate_left()
        return moved

    def playable(self):
        return any(flick(Game(self.board, verbose=False))
                   for flick in (Game.flick_left, Game.flick_right,
                                 Game.flick_up, Game.flick_down))

    def put_tile(self):
        zeros = [(y, x)
                 for y in range(SIZE)
                 for x in range(SIZE)
                 if self.board[y][x] == 0]
        y, x = random.choice(zeros)
        self.board[y][x] = random.choice((2, 4))


def play():
    game = Game()
    game.put_tile()
    game.put_tile()
    game.show()
    key_flick = {'r': game.flick_right,
                 'l': game.flick_left,
                 'u': game.flick_up,
                 'd': game.flick_down}
    try:
        count = 0
        while game.playable():
            key = input(f'input {count}th move>>> ')
            if key not in key_flick:
                print('err')
            elif key_flick[key]():
                game.put_tile()
                game.show()
                print(f'score = {game.score}')
                count += 1
    except (KeyboardInterrupt, EOFError):
        print()
    print('#######################')
    print('Game Over')
    print(f'Final Score = {game.score}')
    print('#######################')


if __name__ == '__main__':
    play()

game2048_test.py

from game2048 import Game

def flick_left_test():
    """
    >>> game = Game()
    >>> game.flick_left()
    False
    >>> game.board
    [[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0]]
    >>> game.score
    0
    >>> game = Game([[2,0,0,0],[2,4,0,0],[2,4,2,0],[2,4,2,4]])
    >>> game.flick_left()
    False
    >>> game.board
    [[2, 0, 0, 0], [2, 4, 0, 0], [2, 4, 2, 0], [2, 4, 2, 4]]
    >>> game.score
    0
    >>> game = Game([[0,0,0,0],[0,0,0,2],[0,0,2,0],[0,0,2,2]])
    >>> game.flick_left()
    2+2=4
    True
    >>> game.board
    [[0, 0, 0, 0], [2, 0, 0, 0], [2, 0, 0, 0], [4, 0, 0, 0]]
    >>> game.score
    4
    >>> game = Game([[0,2,0,0],[0,2,0,2],[0,2,2,0],[0,2,2,2]])
    >>> game.flick_left()
    2+2=4
    2+2=4
    2+2=4
    True
    >>> game.board
    [[2, 0, 0, 0], [4, 0, 0, 0], [4, 0, 0, 0], [4, 2, 0, 0]]
    >>> game.score
    12
    >>> game = Game([[2,0,0,0],[2,0,0,2],[2,0,2,0],[2,0,2,2]])
    >>> game.flick_left()
    2+2=4
    2+2=4
    2+2=4
    True
    >>> game.board
    [[2, 0, 0, 0], [4, 0, 0, 0], [4, 0, 0, 0], [4, 2, 0, 0]]
    >>> game.score
    12
    >>> game = Game([[2,2,0,0],[2,2,0,2],[2,2,2,0],[2,2,2,2]])
    >>> game.flick_left()
    2+2=4
    2+2=4
    2+2=4
    2+2=4
    2+2=4
    True
    >>> game.board
    [[4, 0, 0, 0], [4, 2, 0, 0], [4, 2, 0, 0], [4, 4, 0, 0]]
    >>> game.score
    20
    >>> game = Game([[4,4,4,4],[4,4,4,2],[4,4,2,4],[4,4,2,2]])
    >>> game.flick_left()
    4+4=8
    4+4=8
    4+4=8
    4+4=8
    4+4=8
    2+2=4
    True
    >>> game.board
    [[8, 8, 0, 0], [8, 4, 2, 0], [8, 2, 4, 0], [8, 4, 0, 0]]
    >>> game.score
    44
    >>> game = Game([[4,2,4,4],[4,2,4,2],[4,2,2,4],[4,2,2,2]])
    >>> game.flick_left()
    4+4=8
    2+2=4
    2+2=4
    True
    >>> game.board
    [[4, 2, 8, 0], [4, 2, 4, 2], [4, 4, 4, 0], [4, 4, 2, 0]]
    >>> game.score
    16
    >>> game = Game([[2,4,4,4],[2,4,4,2],[2,4,2,4],[2,4,2,2]])
    >>> game.flick_left()
    4+4=8
    4+4=8
    2+2=4
    True
    >>> game.board
    [[2, 8, 4, 0], [2, 8, 2, 0], [2, 4, 2, 4], [2, 4, 4, 0]]
    >>> game.score
    20
    >>> game = Game([[2,2,4,4],[2,2,4,2],[2,2,2,4],[2,2,2,2]])
    >>> game.flick_left()
    2+2=4
    4+4=8
    2+2=4
    2+2=4
    2+2=4
    2+2=4
    True
    >>> game.board
    [[4, 8, 0, 0], [4, 4, 2, 0], [4, 2, 4, 0], [4, 4, 0, 0]]
    >>> game.score
    28
    """

def rotate_test():
    """
    >>> game = Game([[1,2,3,4],[5,6,7,8],[9,10,11,12],[13,14,15,16]])
    >>> game.rotate_left()
    >>> game.board
    [[4, 8, 12, 16], [3, 7, 11, 15], [2, 6, 10, 14], [1, 5, 9, 13]]
    >>> game = Game([[1,2,3,4],[5,6,7,8],[9,10,11,12],[13,14,15,16]])
    >>> game.rotate_right()
    >>> game.board
    [[13, 9, 5, 1], [14, 10, 6, 2], [15, 11, 7, 3], [16, 12, 8, 4]]
    >>> game = Game([[1,2,3,4],[5,6,7,8],[9,10,11,12],[13,14,15,16]])
    >>> game.rotate_turn()
    >>> game.board
    [[16, 15, 14, 13], [12, 11, 10, 9], [8, 7, 6, 5], [4, 3, 2, 1]]
    """

if __name__ == '__main__':
    import doctest
    doctest.testmod()