log an error
scrapy test scrapy bench
Appear
AttributeError: 'NoneType' object has no attribute 'nextcall'
The meaning of the error : an object does not have a nextcall attribute
According to error analysis
Traceback (most recent call last):
File "D:\pythoninstalllive\lib\site-packages\twisted\internet\defer.py", line 857, in _runCallbacks
current.result = callback( # type: ignore[misc]
File "D:\pythoninstalllive\lib\site-packages\scrapy\core\engine.py", line 187, in <lambda>
d.addBoth(lambda _: self.slot.nextcall.schedule())
Find out where the error occurred
def _next_request_from_scheduler(self) -> Optional[Deferred]:
assert self.slot is not None # typing
assert self.spider is not None # typing
request = self.slot.scheduler.next_request()
if request is None:
return None
d = self._download(request, self.spider)
d.addBoth(self._handle_downloader_output, request)
d.addErrback(lambda f: logger.info('Error while handling downloader output',
exc_info=failure_to_exc_info(f),
extra={'spider': self.spider}))
d.addBoth(lambda _: self.slot.remove_request(request))
d.addErrback(lambda f: logger.info('Error while removing request from slot',
exc_info=failure_to_exc_info(f),
extra={'spider': self.spider}))
# d.addBoth(lambda _: self.slot.nextcall.schedule())
d.addErrback(lambda f: logger.info('Error while scheduling new request',
exc_info=failure_to_exc_info(f),
extra={'spider': self.spider}))
return d
Try to comment out the error line and run the scrap bench again
Result: OK
Analysis: It should be that a dependent library of scrapy has changed, and an object attribute is deleted. Simply, the error line has little effect on the program, just comment it