Example BTC Markets websocket api implementation

btcmarkets.py

#!/usr/bin/env python

"""
btcmarkets.py

usage: python btcmarkets.py 'socket.btcmarkets.net' 443

Example BTC Markets websocket api implementation based on
https://github.com/BTCMarkets/API/wiki/websocket

BTC Markets uses a Socket.IO server. This uses an initial https connection
that is then upgraded to wss (RFC6455). For the Socket.IO protocol, see
(https://github.com/socketio/engine.io-protocol).

This script connects to the websocket endpoint and returns ticker 
information as it is received from the server.

Created by Frank Zhao (https://github.com/frankzhao)
"""

import websockets
import sys
import logging
import asyncio
import json
from six.moves.urllib.parse import urlencode

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger('btcmarkets')


async def connect(server, port):
    logger.info("Connecting to: %s:%d" % (server, port))
    query_params = {
        'EIO': 3,
        'transport': 'websocket'
    }
    wss_url = 'wss://' + server + ':' + str(port) + '/socket.io/?' + urlencode(query_params)
    async with websockets.connect(wss_url) as websocket:  # type: websockets.client.WebSocketClientProtocol
        json_decoder = json.JSONDecoder()
        response = await websocket.recv()
        response = json_decoder.decode(response[1:])  # type: dict
        sid = response.get('sid')
        ping_timeout = response.get('pingTimeout')
        logger.debug("< Received session ID: {}".format(sid))

        packet = await websocket.recv()
        try:
            assert packet == '40'
        except AssertionError:
            logging.error("Connection failed! Server response: %s", packet)

        websocket.timeout = int(ping_timeout)
        await websocket.ping()
        await websocket.send('42' + '[\"join\", \"Ticker-BTCMarkets-BTC-AUD\"]')    # mock socket.emit()
        try:
            while True:
                packet = await websocket.recv()
                logger.info(packet)  # this is the ticker info
                await websocket.pong()
        except KeyboardInterrupt:
            websocket.close()


if __name__ == '__main__':
    if len(sys.argv) != 3:
        sys.stderr.write('usage: python btcmarkets.py <server> <port>\n')
        sys.exit(1)

    server = sys.argv[1]
    port = int(sys.argv[2])

    asyncio.get_event_loop().run_until_complete(connect(server, port))

Hey, so I tacked this problem a couple of weeks ago, my result is here:

https://gist.github.com/aljp/cb7a85e4f3f1352bbf66165150961892

It could probably be a bit more robust (i.e. checking the connection response), however it does deal with sending the heartbeat according to the pingInterval, and also recovers the websocket connection when CloudFlare's proxy (or something) kills the connection because it is idle.