Владимир Сергеевич

l = [ 1, [ 2, 3 ], [ 4, [ 5, 6 ] ] ]
def func(_list):
    _l = []
    for _i in _list:
        if isinstance(_i, list):
            _l.append(deep_map(_i))
        else:
            _l.append(_i*2)
    return _l
print(deep_map(l))