import asyncio
from aiozaifapi.client import ZaifPublicApi

async def last_price(z, **kwargs):
    print(await z.last_price(**kwargs))


loop = asyncio.get_event_loop()
z = ZaifPublicApi(api_url=api_url)
tasks = [
    asyncio.ensure_future(fetch(z, currency_pair='btc_jpy')),
    asyncio.ensure_future(fetch(z, currency_pair='eth_jpy')),
]
loop.run_until_complete(asyncio.gather(*tasks))
loop.close()