def slice(rec, start=0, end=0):
    """
    Slices a BioPython Sequence record
    """

    # Nothing needs to be done
    if not (start or end):
        return rec

    # There is end but no start
    if end and not start:
        start = 1

    # There start but no end
    if start and not end:
        end = len(rec.seq)

    rec.seq = rec.seq[start - 1:end]
    rec.description = f"{start}:{end} {rec.description}"
    return rec