def verify_checksum(*lines):
    """Verify the checksum of one or more TLE lines.

    Raises `ValueError` if any of the lines fails its checksum, and
    includes the failing line in the error message.

    """
    for line in lines:
        checksum = line[68:69]
        if not checksum.isdigit():
            continue
        checksum = int(checksum)
        computed = compute_checksum(line)
        if checksum != computed:
            complaint = ('TLE line gives its checksum as {}'
                         ' but in fact tallies to {}:\n{}')
            raise ValueError(complaint.format(checksum, computed, line))
Verify the checksum of one or more TLE lines.

    Raises `ValueError` if any of the lines fails its checksum, and
    includes the failing line in the error message.