Asyncio concurrency

asyncio_queue.py

import asyncio

q = asyncio.Queue()


async def produce():
    for i in range(10):
        await q.put(i)


async def consume():
    while True:
        try:
            value = q.get_nowait()
        except asyncio.QueueEmpty:
            return
        await asyncio.sleep(0.5)
        print("Consumed", value)


loop = asyncio.get_event_loop()
loop.create_task(produce())
f = asyncio.gather(consume(), consume(), consume())
loop.run_until_complete(f)
loop.close()

concurrent_download.py

import asyncio
import aiohttp


async def download(url):
    s = loop.time()
    with aiohttp.ClientSession(loop=loop) as session:
        async with session.get(url) as r:
            print(url, 'connected')
            text = await r.text()
    t = loop.time() - s
    r = '{:20s} response: {:<4d} size: {:<7d} time: {:0.3f}s'.format(url, r.status, len(text), t)
    print(r)
    return t

# approximately slowest to fastest order
urls = [
    'https://yahoo.com',
    'https://microsoft.com',
    'https://github.com',
    'https://facebook.com',
    'https://google.com',
    'https://bbc.co.uk',
]

loop = asyncio.get_event_loop()

cos = [download(u) for u in urls]

f = asyncio.gather(*cos)
loop.run_until_complete(f)
total_time = sum(f.result())
print('total time {:0.3f}s'.format(total_time))
loop.close()