def print_packet_count():
    """Print the number of packets grouped by packet name."""
    for name in archive.list_packet_names():
        packet_count = 0
        for group in archive.list_packet_histogram(name):
            for rec in group.records:
                packet_count += rec.count
        print('  {: <40} {: >20}'.format(name, packet_count))
Print the number of packets grouped by packet name.