从元组列表中删除大多数嵌套列表括号

Question

I work with a 3D List and want to remove the most nested brackets and comma of the list.

My original list looks like this:

[[[2.250922, 48.867699], [2.250805, 48.867744], [2.250688, 48.867699], [2.250688, 48.867611], [2.250805, 48.867566], [2.250922, 48.867611], [2.250922, 48.867699]], [[2.251038, 48.867832], [2.250922, 48.867877], [2.250805, 48.867832], [2.250805, 48.867744], [2.250922, 48.867699], [2.251038, 48.867744], [2.251038, 48.867832]]]

I like to remove the square brackets and the comma, which divides the values inside the brackets so it looks more like this:

[[2.250922 48.867699, 2.250805 48.867744, 2.250688 48.867699, 2.250688 48.867611, 2.250805 48.867566, 2.250922 48.867611, 2.250922 48.867699], [2.251038 48.867832, 2.250922 48.867877, 2.250805, 48.867832, 2.250805 48.867744, 2.250922 48.867699, 2.251038 48.867744, 2.251038 48.867832]]

I already tried to use functions for flattening the list, but in that case only the outer brackets got removed. Further, I tried to use following function:

new_list = [[item[0] for item in inner_list] for inner_list in outer_list]

Yet, in that instance I lose half of my values inside the brackets (all values with 48.xx). Is there a solution to this problem?

Answer 1

try with this:

    original_list = [[[2.250922, 48.867699], [2.250805, 48.867744], [2.250688, 48.867699], [2.250688, 48.867611], [2.250805, 48.867566], [2.250922, 48.867611], [2.250922, 48.867699]], [[2.251038, 48.867832], [2.250922, 48.867877], [2.250805, 48.867832], [2.250805, 48.867744], [2.250922, 48.867699], [2.251038, 48.867744], [2.251038, 48.867832]]]
    new_list = [[num for sub_l in l for num in sub_l] for l in original_list]
    print(new_list)

Answer 2

For nested lists, I use the following function:

def flatten(iterable):
    for item in iterable:
        if isinstance(item, (list, tuple, set)):
            yield from flatten(item)
        else:
            yield item


flat_list = list(flatten(nested_list))

If you want to keep the structure [[list_1], [list_2]] instead of [list_1, list_2] , then:

semi_flat_list = [list(flatten(item)) for item in nested_list]