import itertools


def flatten(list_of_iters):
    """flatten
    Flattens a list of iterables into a single flat list.
    
    Parameters
    ----------
    list_of_iters : :obj:`iter` of :obj:`iter` 
        A list of iterables.
    
    Returns
    -------
    :obj:`generator` 
        Generates flattened list.
    """
    return itertools.chain(*list_of_iters)