def flatten(nested_list):
return it.chain.from_iterable(nested_list)<EOL>
Transforms a nested iterable into a flat iterable.

This is simply an alias for `itertools.chain.from_iterable`

Args:
    nested_list (Iterable[Iterable]): list of lists

Returns:
    Iterable: flattened items

Example:
    >>> import ubelt as ub
    >>> nested_list = [['a', 'b'], ['c', 'd']]
    >>> list(ub.flatten(nested_list))
    ['a', 'b', 'c', 'd']