Python - Extracting inner most lists

Question

Just started toying around with Python so please bear with me :)

Assume the following list which contains nested lists:

[[[[[1, 3, 4, 5]], [1, 3, 8]]         


        

Answer 1

This seems to work, assuming no 'mixed' lists like [1,2,[3]]:

def get_inner(nested):
    if all(type(x) == list for x in nested):
        for x in nested:
            for y in get_inner(x):
                yield y
    else:
        yield nested

Output of list(get_inner(nested_list)):

[[1, 3, 4, 5], [1, 3, 8], [1, 7, 8], [6, 7, 8], [9]]

Or even shorter, without generators, using sum to combine the resulting lists:

def get_inner(nested):
    if all(type(x) == list for x in nested):
        return sum(map(get_inner, nested), [])
    return [nested]