def convert_trunc(raw):
    """
    Convert the turnc value to a tuple of (True, False) to indicate if it is 5'
    or 3' truncated.
    """

    if isinstance(raw, tuple):
        return raw
    if raw == "no":
        return (False, False)
    if raw == "5'":
        return (True, False)
    if raw == "3'":
        return (False, True)
    if raw == "5'&3'":
        return (True, True)
    raise Exception("Unknown yes/no %s" % raw)