def spandex_dataset_ids(input_file):
    """
    Read all dataset IDs currently in the Spandex index.

    Args:
        input_file (str): The path to a flat file with a list of dataset IDs currently in spandex

    Returns:
        A set of dataset IDs
    """
    return {x.strip() for x in open(input_file, "r") if x.strip()}