[FIXED] How to run multiple websocket API calls concurrently?

Issue

In the code below I'm making two calls to two different APIs. However, instead of running the calls one after the other I would like to run them concurrently. I understand there may be different ways of doing this and I was wondering if there is a prefered way?

import asyncio
import websockets
import json

omsg = {"op": "subscribe", "args": [{"channel": "instruments", "instType": "FUTURES"}]}

dmsg = {"jsonrpc": "2.0", "method": "public/get_index_price", "id": 1, "params": {"index_name": "btc_usd"}}

async def call_oapi(omsg):
    async with websockets.connect('wss://wspap.okx.com:8443/ws/v5/public?brokerId=9999') as websocket:
        await websocket.send(omsg)
        response1 = await websocket.recv()
        response2 = await websocket.recv()
        print(response1)
        print(response2)

async def call_dapi(dmsg):
    async with websockets.connect('wss://test.deribit.com/ws/api/v2') as websocket:
        await websocket.send(dmsg)
        response = await websocket.recv()
        print(response)
        
def run(call_api, msg):
    asyncio.get_event_loop().run_until_complete(call_api(json.dumps(msg)))

run(call_dapi, dmsg)
run(call_oapi, omsg)

Solution

Instead of

def run(call_api, msg):
    asyncio.get_event_loop().run_until_complete(call_api(json.dumps(msg)))

run(call_dapi, dmsg)
run(call_oapi, omsg)

Use

async def main():
    await asyncio.create_task(call_dapi(json.dumps(dmsg)))
    await asyncio.create_task(call_oapi(json.dumps(omsg)))

asyncio.run(main())

You can do something similar with asyncio.gather but it is not the same. I think you want the above code.

• ref: https://docs.python.org/3/library/asyncio-task.html#running-an-asyncio-program
• ref: https://docs.python.org/3/library/asyncio-task.html#asyncio.create_task
• ref: https://docs.python.org/3/library/asyncio-task.html#asyncio.gather

Answered By - amirouche