def create_np_dtype(py_obj, h_group, call_id=0, **kwargs):
    """ dumps an np dtype object to h5py file

    Args:
        py_obj: python object to dump; should be a numpy scalar, e.g. np.float16(1)
        h_group (h5.File.group): group to dump data into.
        call_id (int): index to identify object's relative location in the iterable.
    """
    d = h_group.create_dataset('data_%i' % call_id, data=[str(py_obj)])
    d.attrs['type'] = [b'np_dtype']
