def unset(self, x, y):
x = normalize(x)<EOL>y = normalize(y)<EOL>col, row = get_pos(x, y)<EOL>if type(self.chars[row][col]) == int:<EOL><INDENT>self.chars[row][col] &= ~pixel_map[y % <NUM_LIT:4>][x % <NUM_LIT:2>]<EOL><DEDENT>if type(self.chars[row][col]) != int or self.chars[row][col] == <NUM_LIT:0>:<EOL><INDENT>del(self.chars[row][col])<EOL><DEDENT>if not self.chars.get(row):<EOL><INDENT>del(self.chars[row])<EOL><DEDENT>
Unset a pixel of the :class:`Canvas` object.

        :param x: x coordinate of the pixel
        :param y: y coordinate of the pixel