>>> loop = asyncio.get_event_loop()
>>> print(loop.is_closed())
True

一般来说这结果都是True, 也就是说 loop 是结束的

loop.run_until_complete(main(loop))

loop.run_until_complete 一开始就发现 loop closed, raise RuntimeError(‘Event loop is closed’)

什么都没作, 马上结束返回.

# loop = asyncio.get_event_loop()
loop = asyncio.new_event_loop()

修改如上, 就 OK 了 !

@Jason990420 我按照你说的改了一样会报RuntimeError: Event loop is closed

协程方法

t2 = time.time()
loop = asyncio.new_event_loop()
#loop = asyncio.get_event_loop()  # 创建一个事件循环对象loop
try:
    loop.run_until_complete(main(loop))  # 完成事件循环，直到最后一个任务结束
finally:
    loop.close()  # 结束事件循环.
print("Async total time:", time.time() - t2)

奇怪了, 我这OK, 你再加一行看是 True 还是 False

    loop = asyncio.new_event_loop()  # 创建一个事件循环对象loop
    print(loop.is_closed())

试试...

import time
import asyncio
import aiohttp

URL = 'https://www.xiazaiba.com'

async def job(session):
    response = await session.get(URL)
    return str(response.url)

async def main():
    loop = asyncio.get_running_loop()
    async with aiohttp.ClientSession() as session:
        tasks = [loop.create_task(job(session)) for _ in range(5)]
        finished, unfinished = await asyncio.wait(tasks)
        all_results = [r.result() for r in finished]
        print(all_results)

now = time.time()
asyncio.run(main())
print("Async total time:", time.time() - now)

@Jason990420 直接拷贝你的代码,还是这样~win10 1909+python3.8.2正式版.

要崩溃了~ :joy:

@Jason990420 我这is返回都是False

我在MacOS下运行你的代码就正常.........但在win上就不行,都是python3.8.2奇怪咋回事呢这个.

我自己的代码什么都不改在MacOS 10.15.4最新版系统上也正常,Mac上python也是3.8.2我要崩溃了.

我原本是3.7.6, 改为3.8.2, 也出问题了, 一樣是
RuntimeError: Event loop is closed

你原本的代码除出错外, 有先出现那5个网址吗? 我跑你的原代码出错的是

>>> loop = asyncio.get_event_loop()
RuntimeError: There is no current event loop in thread 'MainThread'.

@Jason990420 非常感谢,为我排错还特意升级了版本,再次感谢,您所说的问题.

我用我自己的代码,会先出5个普通方法的返回,然后会出现一个列表就是携程后的结果,然后出现一大批RuntimeError: Event loop is closed

截图如下

try this …

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import time
import asyncio
import aiohttp
import selectors

URL = 'https://www.xiazaiba.com'

async def job(session):
    response = await session.get(URL)
    return str(response.url)


async def main(loop):
    async with aiohttp.ClientSession() as session:
        tasks = [loop.create_task(job(session)) for _ in range(5)]
        finished, unfinished = await asyncio.wait(tasks)
        all_results = [r.result() for r in finished]  # 得到工作回报.
        print(all_results)


if __name__ == '__main__':
    t2 = time.time()
    # loop = asyncio.get_event_loop()           # Removed
    selector = selectors.SelectSelector()       # New line
    loop = asyncio.SelectorEventLoop(selector)  # New line
    try:
        loop.run_until_complete(main(loop))  # 完成事件循环，直到最后一个任务结束
    finally:
        loop.close()  # 结束事件循环.
    print("Async total time:", time.time() - t2)

我仔细看了下,我自己的代码都是RuntimeError: Event loop is closed没有RuntimeError: There is no current event loop in thread 'MainThread'.

@Jason990420 非常感谢您的解答,请问为什么3.76没有问题,Mac也没问题,您换了跟我一样的3.8.2会出现这样的问题?问题在哪里?是python3.8.2的Bug吗?谢谢~

上面的代码 3.8.2 OK 吗?

@Jason990420 OK了,请教下这是什么问题导致啊?

Platform Support

The asyncio module is designed to be portable, but some platforms have subtle differences and limitations due to the platforms’ underlying architecture and capabilities.

** Changed in version 3.8: On Windows, ProactorEventLoop is now the default event loop. **

All event loops on Windows do not support the following methods:

loop.create_unix_connection() and loop.create_unix_server() are not supported. The socket.AF_UNIX socket family is specific to Unix.

loop.add_signal_handler() and loop.remove_signal_handler() are not supported.

ProactorEventLoop has the following limitations:

The loop.add_reader() and loop.add_writer() methods are not supported.

@Jason990420 再次感谢