Asyncio simple demonstration

demo.py

"""
The idea of this piece of code is to demonstrate how asyncio 
works so you can understand the benefits of using it in your
IO-demansind apps.

The application creates a defined number of workers that will
generate a request to a website for a randomly-generated numbers
and will return the sum.

Note that when running the code workers will be created immediately,
then the application will wait until all results are available and
finally returning the list of sums.

You may vary the number of workers and see the impact in time.
You should see that a higher number of workers do not impact that
much in the amount of time your application takes to run. Of course
the result may be altered by the way the accessed server operates.
"""

import asyncio
import json
import time
import aiohttp

async def worker(name, n, session):
    print(f'worker-{name}')
    url = f'https://qrng.anu.edu.au/API/jsonI.php?length={n}&type=uint16'
    response = await session.request(method='GET', url=url)
    value = json.loads(await response.text())

    return sum(value['data'])


async def main():
    async with aiohttp.ClientSession() as session:
        sums = await asyncio.gather(*(worker(i, n, session) for i, n in enumerate(range(2, 20))))
        print(f'sums: {sums}')


if __name__ == '__main__':
    start = time.perf_counter()
    asyncio.run(main())
    elapsed = time.perf_counter() - start
    print(f'executed in {elapsed:0.2f} seconds.')