"""This module contains the Square class."""


class Square:
    """A Square object represents a square on the board.

    The square's content will consist of a set of possible values for that
    square.
    The grid attribute identifies in which 9x9 grid the square belongs to.
    """

    def __init__(self, line, column, content):
        self.line = line
        self.column = column
        self.grid = self.compute_grid()
        self.coordinates = (self.line, self.column)
        self.content = content

    def compute_grid(self):
        """Given the coordinates, determine which grid the Square belongs to.

        The grids are numbered from 0 to 8, in the following configuration:
            0 1 2
            3 4 5
            6 7 8
        """