Sokoban template

sokoban.py

class Box:
    def __init__(self,r,c,board):
        pass

class Player:
    def __init__(self,r,c,board):
        pass

    def move_up(self):
        pass
    
    def move_down(self):
        pass
    
    def move_left(self):
        pass
    
    def move_right(self):
        pass
    
class Exit:
    def __init__(self,r,c,board):
        pass
    
class Board:
    def __init__(self, board_lines):
        self.player = Player(0, 0, self)
        pass

    def show_board(self):
        pass

    def is_over(self):
        return False

def main():
    board = Board(['..#####.',
                   '###...#.',
                   '#*AO..#.',
                   '###.O*#.',
                   '#*##O.#.',
                   '#.#.*.##',
                   '#O.0OO*#',
                   '#...*..#',
                   '########',])
    
    player = board.player
    step = 0
    
    while not board.is_over():
        step += 1
        print('Step:', step, 'Current board is:')
        
        board.show_board()
        
        print('Pick direction L,R,U,D')
        movement = input()
        if movement == 'U':
            player.move_up()
        elif movement == 'D':
            player.move_down()
        elif movement == 'L':
            player.move_left()
        elif movement == 'R':
            player.move_right()

    print('You use',step,'steps')


    
if __name__ == '__main__':
    main()