python asyncio REST api调用出错

如果只需要调用API,而不考虑结果,则可以在另一个线程中使用执行器,这不会阻塞主线程。

在执行器中运行,使用 AbstractEventLoop.run_in_executor() 遗嘱执行人 concurrent.futures .

对于当前示例,您需要在某个地方运行循环(例如,如果您有某个web服务器或工作者- loop.run_forever() )

带运行循环的固定代码示例

import asyncio


async def callCoroutine(data):
    print('This is data: %s' % data)


def lambda_handler(event, context):   
    loop = asyncio.get_event_loop()
    task = loop.create_task(callCoroutine(context))
    return

lambda_handler(None, {'a': 1})

loop = asyncio.get_event_loop()
loop.run_forever()

举例说明 run_in_executor()

import asyncio
import requests


def call_rest_api(data):
    print('Triggered REST API in background')
    response = requests.get(data['url'])
    print('Response: %s' % response)


async def main(loop):
    print('Some operations here...')

    data = {'url': 'http://example.com#some_rest_api'}
    loop.run_in_executor(None, call_rest_api, data)

    print('Continue work of main thread...')


if __name__ == '__main__':
    loop = asyncio.get_event_loop()
    loop.run_until_complete(main(loop))

简单的例子 await (如果需要同步调用API)

但是,如果要编写同步代码,则不必使用asyncio。

import asyncio
import requests


def call_rest_api(data):
    print('Triggered REST API in background')
    response = requests.get(data['url'])
    print('Response: %s' % response)


async def main(loop):
    print('Some operations here...')

    data = {'url': 'http://example.com#some_rest_api'}
    await call_rest_api(data)

    print('Continue work of main thread...')


if __name__ == '__main__':
    loop = asyncio.get_event_loop()
    loop.run_until_complete(main(loop))

你能提供一个更详细的例子来说明你所拥有的和你想要达到的目标吗?

在您的例子中,主线程是同步运行的。 所以您需要在另一个线程中使用 asyncio.run_coroutine_threadsafe .

import asyncio
import threading

# Run asyncio loop in other thread
loop = asyncio.new_event_loop()
threading.Thread(target=loop.run_forever).start()


async def call_coroutine(data):
    # call a REST API 
    return


def lambda_handler(event, context):   
    # Run the coroutine on the loop of other thread
    future = asyncio.run_coroutine_threadsafe(call_coroutine(data), loop)
    # If need to get result: 
    result = future.result()  # This will block the main thread

    do_something_else()
    return

# If need to stop the asyncio loop
loop.call_soon_threadsafe(loop.stop)