Async Bittrex Orderbook

# -*- coding: utf-8 -*-

import asyncio
import os
import sys

if not sys.version >= '3.6':
   print('This script requires Python 3.6+')
   sys.exit()


import ccxt.async_support as ccxt  # noqa: E402


async def poll():
   exchange = ccxt.bittrex()
   while True:
       yield await exchange.fetch_order_book('BTC/USDT')
       await asyncio.sleep(exchange.rateLimit / 1000)


async def main():
   async for orderbook in poll():
       print(orderbook['bids'][0], orderbook['asks'][0])


asyncio.run(main())