Python coroutine created with 'async' keyword (Python 3.5+) can be awaited, however, the outer most one can't be awaited as Python says "SyntaxError: 'await' outside function"
import asyncio as aio
async def f():
print(1)
await aio.sleep(3)
print(2)
return 3
print(await f())
How to 'await' the 'f' function in the example above?
If you use Python 3.7+, the syntax is even simpler (no need to manually create a loop etc.):
import asyncio as aio
async def f():
print(1)
await aio.sleep(3)
print(2)
return 3
print(aio.run(f())
It's not possible to await at global scope, instead, run an event loop as below:
import asyncio as aio
async def f():
print(1)
await aio.sleep(3)
print(2)
return 3
def fdone(r):
print(r.result())
loop = aio.get_event_loop()
t = loop.create_task(f())
t.add_done_callback(fdone)
loop.run_until_complete(t)
print(4)
print(loop.run_until_complete(f())) would work just as well, asrun_until_complete() will automatically create the task. You don't need add_done_callback because run_until_complete() returns the result of the awaitable it received.