print json.dumps(get_sniffer_data(), sort_keys=True, indent=4, separators=(',', ': '))

data = json.loads(send_command('print_all').decode('utf-8', 'ignore').encode('utf-8'))

raise SerialException('write failed: {}'.format(v))

print json.dumps(get_sniffer_data(), sort_keys=True, indent=4, separators=(',', ': '))

         ^