[Python] Flatten a list with arbitrary dimensions

flatten.py

def flatten(l, result=[]):
    """Flatten a list with arbitrary dimensions.

    Args:
        l (List[Any]): The list to flatten.

    Returns:
        List[Any]: Flattened list.

    """
    for item in l:
        if isinstance(item, Iterable) and not isinstance(item, str):
            reduce(item, result)
        else:
            result.append(item)
    return result