Python - How to sort multidimensional list to two-dimensional list?

Question

How i can sort multidimensional list to two-dimensional list?

Multidimensional input: [8, [6, 7, [-1], [4, [[10]]], 2], 1]

Desired two-dimension

Answer 1

The recursive approach taken by the other answers comes with the recursion limit imposed by Python and the overhead of two passes. A more efficient one-pass iterative approach is to implement breadth-first search using a queue of tuples of lists and associated depths:

from collections import deque
def flatten(lst):
    output = []
    q = deque([(lst, 0)])
    while q:
        l, depth = q.popleft()
        for i in l:
            if isinstance(i, list):
                q.append((i, depth + 1))
            else:
                while depth >= len(output):
                    output.append([])
                output[-1].append(i)
    return output

so that:

flatten([8, [6, 7, [-1], [4, [[10]]], 2], 1])

returns:

[[8, 1], [6, 7, 2], [-1, 4], [], [10]]