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

More efficient than recursion:

result = []
while lst:
    l = lst.pop(0)
    if type(l[0]) == list:
        lst += [sublst for sublst in l if sublst] # skip empty lists []
    else:
        result.insert(0, l)