Connecting Python Client to Socket.io with custom socket.io events

Question

I have a socket.io server (in node.js) which I'm trying to connect a python client to, mainly to provide a command line interface to my socket server.

I'm using Python's web sockets, however, I've realised that this only supports four "events": on open, on close, on error and on message.

My socket.io server defines custom events such as .on('connection'). How can I emit/receive such custom events in python?

Here is my script so far, which just starts up and closes, and so it does not work. import web socket, requests, thread, time host = 'http://socket-url-server.com'

def on_open(ws):
    def run(*args):
        print 'did connect'
        for i in range(3):
            time.sleep(1)
            result =  ws.recv()
            print 'received:'
            print result
        time.sleep(1)
        ws.close()
        print "thread terminating..."
    thread.start_new_thread(run, ())

def on_message(ws, message):
    print message

def on_error(ws, error):
    print error

def on_close(ws):
    print "### closed ###"

print('Connecting to %s' % host)

socket = host.replace('http://', 'ws://')
print socket
websocket.enableTrace(True)
_ws = websocket.WebSocketApp(socket,
                             on_message = on_message,
                             on_error = on_error,
                             on_close = on_close)
_ws.on_open = on_open
_ws.run_forever()

Which library / method should I use otherwise? If I do a handshake and grab the socket.io server key myself, how can I emit/receive events after that?

I also tried using https://pypi.python.org/pypi/socketIO-client, but its documentation is very poor

I wrote the following script for it below but I get No handlers could be found for logger "socketIO_client" and it just hangs forever.

from socketIO_client import SocketIO, BaseNamespace

class Namespace(BaseNamespace):

    def on_connect(self):
        print '[Connected]'

socketIO = SocketIO('http://socket-server-url.com', 80, Namespace)
socketIO.wait(seconds=1)

Jog Dan Jog Dan · Accepted Answer · 2014-02-11T05:12:46

I met the same question and have worked around this issue on my own. herein I wrote some comments regarding to usage of the library socketIO_client and hope it helps.

Developing environment: Server/Client: nodejs / sio_client written by python

"No handlers could be found for logger "socketIO_client". It means it needs handler for logging stuff. Try "import logging; logging.basicConfig(level=logging.DEBUG)" and it logged.
"socketio_client hangs forever" since it keep reconnecting to the indicated server endlessly, i.e., Namespace object will not be adopted until socketIO object is initialized and returns. I have other thread (called thr_siohandle) which initializes the socketio object and main-thread take usage of queue included in Namespace so as to check if there's responses coming from server. It seems that your server should be accessible all the time before running your sio_client, otherwise it keeps re-connects unless you stop the program. Although you can set wait_for_connection as True to stop it, you must handle socketIO_client.exceptions.ConnectionError by yourself.

FYI

[2014/02/19] Sorry, allow me to append some comments to my answers regarding to py_SIOClient.

Example codes like this:

class ChatNamespace(BaseNamespace):
    def on_connect( self ):
        print "connected."
    def on_sayhello_response( self, data ):
        print "response:", data 

sio = SocketIO(host, port, ChatNamespace)
chatns = sio.define(ChatNamespace, '/chat')

while (1):
    chatns.emit('sayhello', {'name':'John'})
    chatns.wait(1)

Command 'sayhello' in this example will be inactive when the connection is reset, and the Namespace object chatns is no longer accessible (no error emerged either). Therefore, it could be worked around by re-defining the dedicated namespace every time before emitting message since we do not know whenever the connection will be reset (and it doesn't matter in my opinion). Hope it helps for people working on py_SocketIO_Client.

SUPPLEMENT 2014/09/09 As I used node(.js) as backend server, but this library seems not to be update for months and its socket.io supports only on socket.io < 1.0.0. Remind to check your package version please before you choosing this library. Hope it does help ppl facing same problem like mine.

Connecting Python Client to Socket.io with custom socket.io events

1 Answers