def from_board(cls, board):
        '''
        :param Board board: board to represent
        :return: SkinnyBoard to represent the given Board
        '''
        if len(board):
            left = board.left_end()
            right = board.right_end()
        else:
            left = None
            right = None

        return cls(left, right, len(board))
def from_board ( cls , board ) : if len ( board ) : left = board . left_end ( ) right = board . right_end ( ) else : left = None right = None return cls ( left , right , len ( board ) )
:param Board board: board to represent
        :return: SkinnyBoard to represent the given Board