[FIXED] Python 3.6 async function over loop in the simplest way possible

Issue

All I need to do is write a simple async function that returns something. Something akin to

async def diss(lis):
  x = []
  for i in lis:
    x.append(i + 1) #the operation is arbitrary, but the input and output of a list is the desired result
  return x

lis = [1, 2, 3, 4]
res = await diss(lis)

However, this gives me a syntactical error at await diss(lis)

All I have found online were tutorials where something is printed inside the async function but when trying to return something, I always receive a coroutine or future object.

My goal is to essentially have the loop run asynchronously so to improve performance and then have something returned

Solution

Here you go:

import asyncio


async def diss(lis):
  x = []
  for i in lis:
    x.append(i + 1)
  return x


async def main():
  lis = [1, 2, 3, 4]
  res = await diss(lis)
  return res


loop = asyncio.get_event_loop()
res = loop.run_until_complete(main())
print(res)

---

Make sure you understand why and when to use asyncio in the first place. For example, there's no point to make code above asynchronous.

Usually you only may need asyncio when you have multiple I/O operations which you can parallelize with asyncio.gather().

Answered By - Mikhail Gerasimov