Functions and coroutines

import asyncio
import time

A traditional function definition as def shows. Calling it runs the function

def blocking_wait_for(wait_for):
    
    time.sleep(wait_for)
    
    print(f"Done waiting for {wait_for} seconds.")
    
    return wait_for

result = blocking_wait_for(1)
print(result)

Done waiting for 1 seconds.
1

Another function. async def indicates we implement asynchronous functionality. Calling it generates a coroutine. It’s not executed yet! The await statement makes it interruptible.

async def friendly_wait_for(wait_for):
    
    await asyncio.sleep(wait_for)
    
    print(f"Done waiting for {wait_for} seconds.")
    
    return wait_for

coro = friendly_wait_for(1)
coro

<coroutine object friendly_wait_for at 0x108d582b0>

awaiting the coroutine triggers execution. Once execution is finished the result is returned.

result = await coro
print(result)

Done waiting for 1 seconds.
1