original_list = [[3, 1], [4, 2], [5]] new_list = [] for sub in original_list: for num in sub: new_list.append(num) print(new_list)
[3, 1, 4, 2, 5]
[3, 4, 5, 1, 2]
[[3, 1], [4, 2], [5]]
[3, 1, 2, 4, 5]