How to sort liberally-deep list of lists and integers?

Question

Let’s say I have a list like that:

[[5, [2, 1], 3], [3, [8, 7], [2, 1, 3], 2], [[3, 2, 1], 3, -1]]

(each list can store unspecified number of integers and lists in any order).
Rules for sorting:

integers (if any) should be before any list
integers are sorted normally (from lower to higher value)
list is "smaller" than another when the first element is lower, if the same we consider the second element, the third, and so on.
If the list has the same values as another but less, it’s smaller. [1, 2] < [1, 2, 3]

So the final result should be:

[[-1, 3, [1, 2, 3]], [2, 3, [1, 2, 3], [7, 8]], [3, 5, [1, 2]], ]

How to implement that kind of sorting? I’ve tried to pass recursive function as sort key in sorted, but mostly ended with TypeError (< not supported for int and list).

Another example:

[1, 4, 3, [[5, 7, 1, 2], 2, 5, 10, 2], 8, [2, 5, [5, 3, 3]], [2, 5, 10, 2, [1, 2, 5]]]

After sorting :

[1, 3, 4, 8, [2, 2, 5, 10, [1, 2, 5]], [2, 2, 5, 10, [1, 2, 5, 7]], [2, 5, [3, 3, 5]]]

Asked By: Piotr Wasilewicz

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Source

Answer 1

Quick draft:

def big_brain_sort(li: list) -> list:
    list_with_int = []
    list_with_list = []
    for el in li:
        if isinstance(el, int):
            list_with_int.append(el)
        elif isinstance(el, list):
            list_with_list.append(big_brain_sort(el))
    sorted_list_int = sorted(list_with_int)
    for lista in sorted(list_with_list, key=lambda x: (big_brain_sort(x), len(x))):
        sorted_list_int.append(lista)
    return sorted_list_int

Answered By: Marek

Answer 2

Edit: broken, see comments

You could sort in-place with this key function:

def key(x):
    if isinstance(x, int):
        return 0, x
    x.sort(key=key)
    return 1, x

Demo (reporting True for both test cases, Try it online!):

def key(x):
    if isinstance(x, int):
        return 0, x
    x.sort(key=key)
    return 1, x

given = [[5, [2, 1], 3], [3, [8, 7], [2, 1, 3], 2], [[3, 2, 1], 3, -1]]
wanted = [[-1, 3, [1, 2, 3]], [2, 3, [1, 2, 3], [7, 8]], [3, 5, [1, 2]], ]

given.sort(key=key)
print(given == wanted)

given = [1, 4, 3, [[5, 7, 1, 2], 2, 5, 10, 2], 8, [2, 5, [5, 3, 3]], [2, 5, 10, 2, [1, 2, 5]]]
wanted = [1, 3, 4, 8, [2, 2, 5, 10, [1, 2, 5]], [2, 2, 5, 10, [1, 2, 5, 7]], [2, 5, [3, 3, 5]]]

given.sort(key=key)
print(given == wanted)

Answered By: Kelly Bundy

How to sort liberally-deep list of lists and integers?

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