then it is throwing up this text and error message.

pi@raspberrypi:~/AIY-projects-python/src/examples/voice $ ./assistant_grpc_demo.py
DEBUG:requests_oauthlib.oauth2_session:Generated new state nvp5K9TV1TzH8PNnTKYlwvnBsvGbmB.
Traceback (most recent call last):
  File "./assistant_grpc_demo.py", line 57, in <module>
    main()
  File "./assistant_grpc_demo.py", line 49, in main
    language_code=args.language)
  File "/opt/aiy/projects-python/src/aiy/assistant/grpc.py", line 205, in __init__
    super().__init__(language_code, volume_percentage)
  File "/opt/aiy/projects-python/src/aiy/assistant/grpc.py", line 64, in __init__
    credentials = auth_helpers.get_assistant_credentials()
  File "/opt/aiy/projects-python/src/aiy/assistant/auth_helpers.py", line 132, in get_assistant_credentials
    return _try_to_get_credentials(credentials_file)
  File "/opt/aiy/projects-python/src/aiy/assistant/auth_helpers.py", line 123, in _try_to_get_credentials
    credentials = _credentials_flow_interactive(client_secrets)
  File "/opt/aiy/projects-python/src/aiy/assistant/auth_helpers.py", line 76, in _credentials_flow_interactive
    credentials = flow.run_local_server()
  File "/usr/local/lib/python3.5/dist-packages/google_auth_oauthlib/flow.py", line 407, in run_local_server
    host, port, wsgi_app, handler_class=_WSGIRequestHandler)
  File "/usr/lib/python3.5/wsgiref/simple_server.py", line 160, in make_server
    server = server_class((host, port), handler_class)
  File "/usr/lib/python3.5/socketserver.py", line 440, in __init__
    self.server_bind()
  File "/usr/lib/python3.5/wsgiref/simple_server.py", line 51, in server_bind
    HTTPServer.server_bind(self)
  File "/usr/lib/python3.5/http/server.py", line 138, in server_bind
    socketserver.TCPServer.server_bind(self)
  File "/usr/lib/python3.5/socketserver.py", line 454, in server_bind
    self.socket.bind(self.server_address)
OSError: [Errno 98] Address already in use

i have no idea what it is or how to work around it, any info in the ether please?

markdown added by yawns