Flattens only values in a heirarchical dictionary, keys are nested.

def flatten_dict_vals(dict_):
    """
    Flattens only values in a heirarchical dictionary, keys are nested.
    """
    if isinstance(dict_, dict):
        return dict([
            ((key, augkey), augval)
            for key, val in dict_.items()
            for augkey, augval in flatten_dict_vals(val).items()
        ])
    else:
        return {None: dict_}