Aiohttp、Asyncio：运行时错误：事件循环已关闭

我有两个脚本，scraper.py 和 db_control.py。在 scraper.py 我有这样的东西：

...
def scrape(category, field, pages, search, use_proxy, proxy_file):
    ...
    loop = asyncio.get_event_loop()

    to_do = [ get_pages(url, params, conngen) for url in urls ]
    wait_coro = asyncio.wait(to_do)
    res, _ = loop.run_until_complete(wait_coro)
    ...
    loop.close()
    
    return [ x.result() for x in res ]

...

在 db_control.py 中：

from scraper import scrape
...
while new < 15:
    data = scrape(category, field, pages, search, use_proxy, proxy_file)
    ...
...

理论上，刮刀应该启动未知次数，直到获得足够的数据。但当new不是立即> 15然后出现这个错误：

  File "/usr/lib/python3.4/asyncio/base_events.py", line 293, in run_until_complete
self._check_closed()
  File "/usr/lib/python3.4/asyncio/base_events.py", line 265, in _check_closed
raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed

但如果我只运行 scrape() 一次，脚本就可以正常工作。所以我猜重新创建时存在一些问题loop = asyncio.get_event_loop()， 我努力了this https://stackoverflow.com/questions/32598231/asyncio-runtimeerror-event-loop-is-closed但一切都没有改变。我该如何解决这个问题？当然，这些只是我的代码片段，如果您认为问题可能出在其他地方，可以使用完整代码here https://github.com/kongzii/korpi/tree/master/korpi/lib.

Methods run_until_complete https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.BaseEventLoop.run_until_complete, run_forever https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.BaseEventLoop.run_forever, run_in_executor https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.BaseEventLoop.run_in_executor, create_task https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.BaseEventLoop.create_task, call_at https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.BaseEventLoop.call_at明确检查 循环并在关闭时抛出异常。

引用自文档 -BaseEvenLoop.close https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.BaseEventLoop.close:

这是幂等的并且不可逆转的

除非你有一些（充分的）理由，否则你可以简单地省略结束行：

def scrape(category, field, pages, search, use_proxy, proxy_file):
    #...
    loop = asyncio.get_event_loop()

    to_do = [ get_pages(url, params, conngen) for url in urls ]
    wait_coro = asyncio.wait(to_do)
    res, _ = loop.run_until_complete(wait_coro)
    #...
    # loop.close()
    return [ x.result() for x in res ]

如果你想每次都有一个全新的循环，你不必手动创建它并设置为默认值：

def scrape(category, field, pages, search, use_proxy, proxy_file):
    #...
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)    
    to_do = [ get_pages(url, params, conngen) for url in urls ]
    wait_coro = asyncio.wait(to_do)
    res, _ = loop.run_until_complete(wait_coro)
    #...
    return [ x.result() for x in res ]