Python: use asyncio module to wait result for 2 independent tasks

Question

For Python 3.4+, I can use asyncio to dispatch independent tasks.

Now, I have two long running independent functions. Both functions return result, so how do I collect the two results into a single object, using asyncio to put these two functions inside a IO loop.

import asyncio 

async def long_func1():
   await ...
   ...

async def long_func2():
   await ...
   ...

Answer 1

If I'm getting what you are trying to do...

In order to run both of the function at the same time you can use the asyncio.create_task and asyncio.wait for the results of them.

Have a look at the following example:

import sys
import asyncio

async def test_1():
    return sys._getframe().f_code.co_name

async def test_2():
    return sys._getframe().f_code.co_name


async def main():
    t1 = asyncio.create_task(test_1())
    t2 = asyncio.create_task(test_2())

    done, pending = await asyncio.wait([t1, t2])
    results = [d.result() for d in done]

    # The order of the finished function is unknown
    print(results)

if __name__ == '__main__':
    loop = asyncio.get_event_loop()
    loop.run_until_complete(main())
    loop.close()

It will run two function and will wait for both of them to finish.

Once they are done it will gather the results of both of the done function to the results list.