Python 中的两个独立异步循环

Question

使用async/await?执行在 Python 中并行运行的两个异步循环的好方法是什么？

我也想过类似下面的代码，但不能换我围绕着如何使用头async/ await/EventLoop在这种特殊情况下。

import asyncio

my_list = []

def notify():
    length = len(my_list)
    print("List has changed!", length)

async def append_task():
    while True:
        time.sleep(1)
        await my_list.append(random.random())
        notify()

async def pop_task():
    while True:
        time.sleep(1.8)
        await my_list.pop()
        notify()

loop = asyncio.get_event_loop()
loop.create_task(append_task())
loop.create_task(pop_task())
loop.run_forever()

预期输出：

$ python prog.py
List has changed! 1 # after 1sec
List has changed! 0 # after 1.8sec
List has changed! 1 # after 2sec
List has changed! 2 # after 3sec
List has changed! 1 # after 3.6sec
List has changed! 2 # after 4sec
List has changed! 3 # after 5sec
List has changed! 2 # after 5.4sec

Answer 1

这工作正常：

记：你想等待快速非IO绑定操作（list.append以及list.pop那些甚至没有协程）; 您可以做的是awaitasyncio.sleep(...)（这是一个协程并将控制权交还给调用者）：

import asyncio
import random

my_list = []


def notify():
    length = len(my_list)
    print("List has changed!", length)

async def append_task():
    while True:
        await asyncio.sleep(1)
        my_list.append(random.random())
        notify()

async def pop_task():
    while True:
        await asyncio.sleep(1.8)
        my_list.pop()
        notify()


loop = asyncio.get_event_loop()
cors = asyncio.wait([append_task(), pop_task()])
loop.run_until_complete(cors)

time.sleep本身是阻塞的，不能很好地与await.