D = [] def move_list(a): for i in a : if type(i) != list: D.append(i) else: move_list(i) s=[1,[12,[1,[1,23,4,[1,2,[3]]]]],[3,[1,[2,645,[3,5,[456,[4,[45,7,[2,[[[[[[5]]]]]]]]]]]]],4]] move_list(s) print(D)