dv-websocket.py

import asyncio
import websockets
import hashlib
import hmac
import base64
import time
import json
key = ''
secret = ''
host = 'wss://demo.dvchain.co/websocket'
def get_headers():
    milliseconds = int(round(time.time() * 1000))
    timewindow=2000
    message_bytes = bytes(f'{key}{milliseconds}{timewindow}', 'utf-8')
    secret_bytes = bytes(secret, 'utf-8')
    hash = hmac.new(secret_bytes, message_bytes, hashlib.sha256)
    hash.hexdigest()
    signature = base64.b64encode(hash.digest())
    return [('dv-api-key',key),('dv-timestamp', milliseconds),('dv-timewindow',timewindow),('dv-signature', signature.decode("utf-8"))]
async def start():
  uri = f'{host}'
  headers = get_headers()
  print(headers)
  async with websockets.connect(uri, extra_headers=headers) as websocket:
    available_symbol_request={'type' : 'request-response','event': '1', 'topic': 'availablesymbols' }
    await websocket.send(json.dumps(available_symbol_request))
    available_symbols = await websocket.recv()
    print(available_symbols)
asyncio.get_event_loop().run_until_complete(start())