在python中对非异步函数使用asyncio?

如果某个函数是阻塞的而不是异步的,那么只有正确的方法才能在内部运行它 asyncio 事件循环是在线程内使用 run_in_executor 以下内容:

# Our example blocking functions
import time


def queryFoo():
    time.sleep(3)
    return 'foo'


def queryBar():
    time.sleep(3)
    return 'bar'


# Run them using asyncio
import asyncio
from concurrent.futures import ThreadPoolExecutor


_executor = ThreadPoolExecutor(10)


async def in_thread(func):
    loop = asyncio.get_event_loop()
    return await loop.run_in_executor(_executor, func)


async def main():
    results = await asyncio.gather(
        in_thread(queryFoo), 
        in_thread(queryBar),
    )

    print(results)


if __name__ == "__main__":
    loop = asyncio.get_event_loop()
    try:
        loop.run_until_complete(main())
    finally:
        loop.run_until_complete(loop.shutdown_asyncgens())
        loop.close()

它起作用了。

如果你想避免使用线程,唯一的方法就是重写 queryFoo / queryBar 本质上是异步的。

我想你是在同意之后,希望不要坚持使用 asyncio 模块本身在这种情况下,这个小例子可能会有帮助:

import asyncio
import time
from concurrent.futures import ThreadPoolExecutor

def queryFoo():
    time.sleep(2)
    return "FOO"

def queryBar():
    time.sleep(4)
    return "BAR"

with ThreadPoolExecutor(max_workers=2) as executor:
    foo = executor.submit(queryFoo)
    bar = executor.submit(queryBar)
    results = [foo.result(), bar.result()]

print(results)

两者兼而有之 queryFoo() 和 queryBar() 并行地,并将其结果收集到一个列表中,按照分配给 results 是的。