Test ensure future asyncio

asyncio.py

import asyncio
import concurrent.futures
import functools
import random
import time
import uuid


async def func(_id):
    delay = random.randint(1, 20)
    await asyncio.sleep(delay)
    if delay % 7 == 0:
        raise Exception(f'Failed {_id} with {delay}')
    return _id, delay

def cb(fut):
    try:
        _id, delay = fut.result()
        print(f'Finished {_id} after {delay}.')
    except Exception as e:
        print(e)

async def do():
    tasks = []
    loop = asyncio.get_event_loop()
    for i in range(25):
        _id = uuid.uuid4().hex
        future = asyncio.ensure_future(func(_id))
        future.add_done_callback(cb)
        tasks.append(future)
        print(f'Created {_id}...')

    await asyncio.sleep(5)
    print('Gathering...')
    res = await asyncio.gather(*tasks, return_exceptions=True)


def main():
    loop = asyncio.get_event_loop()

    loop.run_until_complete(do())
    loop.close()

if __name__ == '__main__':
    main()