Aiohttp,Asyncio:RuntimeError:事件循环已关闭

Question

我有两个脚本,scraper.py和db_control.py.在scraper.py我有这样的事情:

...
def scrap(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 scrap
...
while new < 15:
    data = scrap(category, field, pages, search, use_proxy, proxy_file)
    ...
...

从理论上讲,刮板应该在未知时间开始,直到获得足够的数据.但是当new不是imidiatelly > 15然后这个错误发生:

  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

但是如果我只运行一次scrap(),脚本就可以了.所以我觉得重新创建有一些问题loop = asyncio.get_event_loop(),我试过这个但没有改变.我怎么解决这个问题？当然,这些都只是片断我的代码,如果你认为问题可能是在其他地方,充满了代码,请点击这里.

Answer 1

方法run_until_complete,run_forever,run_in_executor,create_task,call_at明确检查的循环,如果它的封闭抛出异常.

从文档引用 - BaseEvenLoop.close:

这是幂等的,不可逆转的

除非你有一些(好的)理由,否则你可能只是省略了关闭线:

def scrap(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 ]

如果您希望每次都有一个全新的循环,您必须手动创建它并设置为默认值:

def scrap(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 ]