python - 如何解决scarpy-redis空跑问题？

问题描述

scrapy-redis框架中，reids存储的xxx:requests已经爬取完毕，但程序仍然一直运行，如何自动停止程序，而不是一直在空跑？

2017-07-03 09:17:06 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)2017-07-03 09:18:06 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)

可以通过engine.close_spider(spider, ’reason’)来停止程序的运行。

def next_request(self):block_pop_timeout = self.idle_before_closerequest = self.queue.pop(block_pop_timeout)if request and self.stats: self.stats.inc_value(’scheduler/dequeued/redis’, spider=self.spider)if request is None: self.spider.crawler.engine.close_spider(self.spider, ’queue is empty’)return request

还有一个问题不明白：当通过engine.close_spider(spider, ’reason’)来关闭spider时，会出现几个错误之后才能关闭。

# 正常关闭2017-07-03 18:02:38 [scrapy.core.engine] INFO: Closing spider (queue is empty)2017-07-03 18:02:38 [scrapy.statscollectors] INFO: Dumping Scrapy stats:{’finish_reason’: ’queue is empty’, ’finish_time’: datetime.datetime(2017, 7, 3, 10, 2, 38, 616021), ’log_count/INFO’: 8, ’start_time’: datetime.datetime(2017, 7, 3, 10, 2, 38, 600382)}2017-07-03 18:02:38 [scrapy.core.engine] INFO: Spider closed (queue is empty)# 之后还会出现几个错误才关闭spider，难道spider刚启动时会启动多个线程一起抓取， # 然后其中一个线程关闭了spider，其他线程就找不到spider才会报错！Unhandled ErrorTraceback (most recent call last): File 'D:/papp/project/launch.py', line 37, in <module> process.start() File 'D:Program Filespython3libsite-packagesscrapycrawler.py', line 285, in start reactor.run(installSignalHandlers=False) # blocking call File 'D:Program Filespython3libsite-packagestwistedinternetbase.py', line 1243, in run self.mainLoop() File 'D:Program Filespython3libsite-packagestwistedinternetbase.py', line 1252, in mainLoop self.runUntilCurrent()--- <exception caught here> --- File 'D:Program Filespython3libsite-packagestwistedinternetbase.py', line 878, in runUntilCurrent call.func(*call.args, **call.kw) File 'D:Program Filespython3libsite-packagesscrapyutilsreactor.py', line 41, in __call__ return self._func(*self._a, **self._kw) File 'D:Program Filespython3libsite-packagesscrapycoreengine.py', line 137, in _next_request if self.spider_is_idle(spider) and slot.close_if_idle: File 'D:Program Filespython3libsite-packagesscrapycoreengine.py', line 189, in spider_is_idle if self.slot.start_requests is not None:builtins.AttributeError: ’NoneType’ object has no attribute ’start_requests’

问题解答

怎样知道放的requests爬取完毕，这个要定义才知道如果不复杂，可以使用内部扩展关掉！

scrapy.contrib.closespider.CloseSpider

CLOSESPIDER_TIMEOUTCLOSESPIDER_ITEMCOUNTCLOSESPIDER_PAGECOUNTCLOSESPIDER_ERRORCOUNThttp://scrapy-chs.readthedocs...