Nested List Flatten

Problem

Flatten a nested list of integers into a single list of integers.

nested is a list whose elements are either integers or other nested lists. Flatten depth-first, preserving the left-to-right order.

Return the flat list.

Hint

Recurse when the element is a list and append otherwise.

case 1

in: [[1,[2,3],4]]

expected: [1,2,3,4]

case 2

in: [[]]

expected: []

case 3

in: [[[1,2],[3,[4,5]]]]

expected: [1,2,3,4,5]

case 4

in: [[[[]]]]

expected: []

Starter codePython

def flatten_nested(nested):
    # Your code here
    pass

4 test cases · run your code against them in the editor