python asyncio

 如下，多个协程可以并行

await异步等待函数返回， 必须写在在 aysnc内。

除了asyncio.gather(), asyncio.sleep(), 还有 asyncio.wait(), asyncio.wait_for()

import asyncio
import aiohttp


async def f1():
    print("f1")
    await asyncio.sleep(1)
    async with aiohttp.ClientSession() as session:
        async with session.get('https://www.baidu.com') as response:
            txt = await response.text()
            print(txt)
    print("f1 end")
    return "f1"

async def f2():
    print("f2")
    await asyncio.sleep(2)
    print("f2 end")
    return "f2"

async def main1():
    result = await asyncio.gather(f1(), f2())
    print(result)

async def main2():
    task1 = asyncio.create_task(f1())
    task2 = asyncio.create_task(f2())
    await task1
    await task2
    

#错误的用法，串行运行的
if __name__ == "__main__":
    asyncio.run(f2())
    asyncio.run(f1())

# 正确的用法
if __name__ == "__main__":
    asyncio.run(main1())


# 正确的用法
if __name__ == "__main__":
    asyncio.run(main2())