python coroutine，asyncio，yield

Posted 2021-05-08

import time
from datetime import datetime
import asyncio

#@ coroutine by yield
def print_message_periodical1(interval_seconds, message='keep alive'):
    while True:
        print(f'{datetime.now()}-{message}')
        start=time.time()
        end=start+interval_seconds
        while True:
            yield
            now=time.time()
            if now>=end:
                break

def coroutine_by_yield():
    a=print_message_periodical1(1, 'one')
    b=print_message_periodical1(3, 'three')
    stack=[a,b]
    while True:
        for task in stack:
            next(task)

#@ coroutine by asyncio
async def print_message_periodical2(interval_seconds,message='keep alive'):
    while True:
        print(f'{datetime.now()}-{message}')
        start = time.time()
        end = start + interval_seconds
        while True:
            await asyncio.sleep(0)
            now = time.time()
            if now >= end:
                break

def coroutine_by_asyncio():
    scheduler=asyncio.get_event_loop()
    scheduler.create_task(print_message_periodical2(1,'one'))
    scheduler.create_task(print_message_periodical2(3,'three'))
    scheduler.run_forever()


if __name__ == '__main__':
    coroutine_by_yield()
    coroutine_by_asyncio()