问大家一个关于 async 和 await 的问题， 新年快乐~

[fanhaipeng0403]

问大家一个问题

    
    

try:
    # pylint: disable=invalid-name
    asyncio_run = asyncio.run  # type: ignore
except AttributeError:
    _T = TypeVar('_T')

    def asyncio_run(main: Awaitable[_T], *, debug: bool = False) -> _T:
        """Minimal re-implementation of asyncio.run (since 3.7)."""
        loop = asyncio.new_event_loop()
        asyncio.set_event_loop(loop)
        loop.set_debug(debug)
        try:
            return loop.run_until_complete(main)
        finally:
            asyncio.set_event_loop(None)
            loop.close()
    
    
    
async def setup_and_run_hass(config_dir: str,
                             args: argparse.Namespace) -> int:
    """Set up HASS and run."""
    from homeassistant import bootstrap, core

    hass = core.HomeAssistant()

    if args.demo_mode:
        config = {
            'frontend': {},
            'demo': {}
        }  # type: Dict[str, Any]
        bootstrap.async_from_config_dict(
            config, hass, config_dir=config_dir, verbose=args.verbose,
            skip_pip=args.skip_pip, log_rotate_days=args.log_rotate_days,
            log_file=args.log_file, log_no_color=args.log_no_color)
    else:
        config_file = ensure_config_file(config_dir)
        print('Config directory:', config_dir)
        await bootstrap.async_from_config_file(
            config_file, hass, verbose=args.verbose, skip_pip=args.skip_pip,
            log_rotate_days=args.log_rotate_days, log_file=args.log_file,
            log_no_color=args.log_no_color)

    if args.open_ui:
        # Imported here to avoid importing asyncio before monkey patch
        from homeassistant.util.async_ import run_callback_threadsafe

        def open_browser(_: Any) -> None:
            """Open the web interface in a browser."""
            if hass.config.api is not None:
                import webbrowser
                webbrowser.open(hass.config.api.base_url)

        run_callback_threadsafe(
            hass.loop,
            hass.bus.async_listen_once,
            EVENT_HOMEASSISTANT_START, open_browser
        )

    return await hass.async_run()
    
    
    
    exit_code = asyncio_run(setup_and_run_hass(config_dir, args))
    if exit_code == RESTART_EXIT_CODE and not args.runner:
        try_to_restart()
        

这里的 exit_code = asyncio_run(setup_and_run_hass(config_dir, args)) 作用是什么，怎么感觉还是要等 setup_and_run_hass 跑完了才继续运行

就是针对一个函数使用 async 的目的，

import  asyncio

try:
    # pylint: disable=invalid-name
    asyncio_run = asyncio.run  # type: ignore
except AttributeError:

    def asyncio_run(main,  debug=False):
        """Minimal re-implementation of asyncio.run (since 3.7)."""
        loop = asyncio.new_event_loop()
        asyncio.set_event_loop(loop)
        loop.set_debug(debug)
        try:
            return loop.run_until_complete(main)
        finally:
            asyncio.set_event_loop(None)
            loop.close()

async def slow_operation_1(m):
    await asyncio.sleep(m)
    print('Slow operation {} complete'.format(m))
    return m
    

        
async def slow_operation_2(n):
    await asyncio.sleep(n)
    print('Slow operation {} complete'.format(n))
    
    return await slow_operation_1(m=n+1)
    
result = asyncio_run(slow_operation_2(2))

print(result)

类似于这段代码。。

[fanhaipeng0403]

In [1]: import asyncio
...:
...: try:
...: # pylint: disable=invalid-name
...: asyncio_run = asyncio.run # type: ignore
...: except AttributeError:
...:
...: def asyncio_run(main, debug=False):
...: """Minimal re-implementation of asyncio.run (since 3.7)."""
...: loop = asyncio.new_event_loop()
...: asyncio.set_event_loop(loop)
...: loop.set_debug(debug)
...: try:
...: return loop.run_until_complete(main)
...: finally:
...: asyncio.set_event_loop(None)
...: loop.close()
...:
...: async def slow_operation_1(m):
...: await asyncio.sleep(m)
...: print('Slow operation {} complete'.format(m))
...: return m
...:
...:
...:
...: async def slow_operation_2(n):
...: await asyncio.sleep(n)
...: print('Slow operation {} complete'.format(n))
...:
...: return await slow_operation_1(m=n+1)
...:
...: result = asyncio_run(slow_operation_2(2))
...:
...: print(result)
...:

Slow operation 2 complete
Slow operation 3 complete
3

[canwushuang]

协程在 loop 内部有效，遇到 io 阻塞则继续运行，而你那个是 loop 外。