def namify(idx):
    """
    Helper function that pads a given file number and return it as per the dataset image name format.
    """
    len_data = 6 #Ilsvr images are in the form of 000000.JPEG
    len_ = len(str(idx))
    need = len_data - len_

    assert len_data >= len_, "Error! Image idx being fetched is incorrect. Invalid value."

    pad = '0'*need

    return pad+str(idx)