def _get_row_or_col(self, num_windows, width, height, xoffset, yoffset):
        """process one row (or col) at a time"""
        rows, cols, orientation = self.calc(num_windows, width, height)
        results = []
        if orientation == ROWCOL:
            x = 0
            y = 0
            for i, col in enumerate(range(cols)):
                w_width = width // cols
                w_height = height // rows
                if i == cols - 1:
                    w_width = width - x
                results.append((x + xoffset, y + yoffset, w_width, w_height))
                x += w_width
        elif orientation == COLROW:
            x = 0
            y = 0
            for i, col in enumerate(range(rows)):
                w_width = width // cols
                w_height = height // rows
                if i == rows - 1:
                    w_height = height - y
                results.append((x + xoffset, y + yoffset, w_width, w_height))
                y += w_height
        return orientation, results
process one row (or col) at a time
libqtile/layout/ratiotile.py