I am attempting to combine four lists of one row and two columns, such as line_parts=[[2, 1], [2, 0], [1, 2], [5, 2]], to create a list of one row and five columns, such as all_lines=[[5, 2, 1, 2, 0]]. However, the list of four 1-line 2-column lists is written as line_parts=[[2, 1], [2, 0], [1...