[Python] deep_flatten

[ropering]

def spread(arg):
    ret = []
    for i in arg:
        if isinstance(i, list):
            ret.extend(i)
        else:
            ret.append(i)
    return ret

def deep_flatten(lst):
    result = []
    result.extend(
        spread(list(map(lambda x: deep_flatten(x) if type(x) == list else x, lst)))
    return result

deep_flatten(1, [2], [[3], 4], 5]) # [1, 2, 3, 4, 5]