lesson05_event.py

# SuperFastPython.com
# example of using an asyncio event object
from random import random
import asyncio

# task coroutine
async def task(event, number):
 # wait for the event to be set
 await event.wait()
 # generate a random value between 0 and 1
 value = random()
 # suspend for a moment
 await asyncio.sleep(value)
 # report a message
 print(f'Task {number} got {value}')

# main coroutine
async def main():
 # create a shared event object
 event = asyncio.Event()
 # create and run the tasks
 tasks = [asyncio.create_task(task(event, i))
 for i in range(5)]
 # allow the tasks to start
 print('Main suspending...')
 await asyncio.sleep(0)
 # start processing in all tasks
 print('Main setting the event')
 event.set()
 # await for all tasks to terminate
 _ = await asyncio.wait(tasks)

# run the asyncio program
asyncio.run(main())