How could a 'byte string' input argument be passed to a python function called from MATLAB ?

I am trying to create a server-client application using ipc, where server is a pure Python application and client is a MATLAB application which calls python functions. I have Anaconda installed with Python 3.7 environment.

Python Server code :

from multiprocessing.connection import Listener

address = ('localhost', 6000)     # family is deduced to be 'AF_INET'
listener = Listener(address, authkey=b'secret password')
conn = listener.accept()
print('connection accepted from', listener.last_accepted)
while True:
    msg = conn.recv()
    print(msg)
    if msg == 'close':
        conn.close()
        break
listener.close()

Python client code :

from multiprocessing.connection import Client

address = ('localhost', 6000)
conn = Client(address, authkey=b'secret password')
conn.send('close')
# can also send arbitrary objects:
# conn.send(['a', 2.5, None, int, sum])
conn.close()

When executed in Python, the above pair is working fine.

Now trying MATLAB equivalent of above Python client code in command line :

>> mp_pyModule = py.importlib.import_module('multiprocessing.connection');
>> client_fn = mp_pyModule.Client;
>> address = py.tuple({'localhost',int16(6000)});
>> conn = client_fn(address,pyargs('authkey','secret password'));
Error using connection>Client (line 495)
Python Error: TypeError: authkey should be a byte string

I require the above argument 'secret password' to be sent as a 'byte string'. Is there any method ?

Unsupported types to Python does not mention anything about this. Is there any other limitation ?

[Walter Roberson]

Try passing uint8('secret password')

[Varun Pai]

conn = client_fn(addr,pyargs('authkey',uint8('secret password')));

It is NOT working. Probably it won't ryt, since it is returning a uint8 row vector.

>> uint8('secret password')
ans =
  1×15 uint8 row vector
   115   101    99   114   101   116    32   112    97   115   115   119   111   114   100

Thanks..

[Walter Roberson]

Try py.bytes(uint8('secret password'))

[Varun Pai]

Kudos Walter !! It worked.