Stream kraken ticker

from sanic import Sanic
from sanic.response import json
from sanic.response import stream
import asyncio
import psycopg2
import ccxt.async_support as ccxt
import json
import logging

logger = logging.getLogger("ozzo")
try:
    conn = psycopg2.connect("dbname='postgres' user='postgres' host='localhost' port='5432' password='password'")
except:
    print("I am unable to connect to the database")

app = Sanic()

kraken = ccxt.kraken({
    'apiKey': "hEvQNMDIeoCJbr7W/ZBb5CGOrx3G0lWF5B3zqa1JBxdZlEaL8EK+D0Mw",
    'secret': "JaE9wI6Nwgh5oRxiHcVxurwzwBxwc05W/qv/k1srGg4s3EYuXPpNkLLM5NYbbWpM8rCyijIeDavRuqWbU0ZV9A==",
})

async def poll(seconds):
    while True:
        try:
            yield await asyncio.Task(kraken.fetch_ticker('BTC/USD'))
        except RuntimeError:
            logger.exception("Something went wrong while calling kraken")
        if seconds * 1000 < kraken.rateLimit:
            raise ("poll rate exceed the rate limit")
        await asyncio.sleep(seconds)

@app.get('/')
async def test(request):
    async def stream_from_exchange(response):
        async for ticker in poll(5):
            payload = json.dumps(ticker)
            print("payload:", payload)
            await response.write(f"{payload}\n")
    return stream(
        stream_from_exchange,
        content_type='application/stream+json'
    )

async def main():
    async for ticker in poll(5):
        print(ticker)


if __name__ == '__main__':
    app.run(host='0.0.0.0', port=8000)