"""
Extension for collecting core stats like items scraped and start/finish times
"""
from datetime import datetime
from scrapy import signals
[docs]class CoreStats:
def __init__(self, stats):
self.stats = stats
self.start_time = None
@classmethod
def from_crawler(cls, crawler):
o = cls(crawler.stats)
crawler.signals.connect(o.spider_opened, signal=signals.spider_opened)
crawler.signals.connect(o.spider_closed, signal=signals.spider_closed)
crawler.signals.connect(o.item_scraped, signal=signals.item_scraped)
crawler.signals.connect(o.item_dropped, signal=signals.item_dropped)
crawler.signals.connect(o.response_received, signal=signals.response_received)
return o
def spider_opened(self, spider):
self.start_time = datetime.utcnow()
self.stats.set_value('start_time', self.start_time, spider=spider)
def spider_closed(self, spider, reason):
finish_time = datetime.utcnow()
elapsed_time = finish_time - self.start_time
elapsed_time_seconds = elapsed_time.total_seconds()
self.stats.set_value('elapsed_time_seconds', elapsed_time_seconds, spider=spider)
self.stats.set_value('finish_time', finish_time, spider=spider)
self.stats.set_value('finish_reason', reason, spider=spider)
def item_scraped(self, item, spider):
self.stats.inc_value('item_scraped_count', spider=spider)
def response_received(self, spider):
self.stats.inc_value('response_received_count', spider=spider)
def item_dropped(self, item, spider, exception):
reason = exception.__class__.__name__
self.stats.inc_value('item_dropped_count', spider=spider)
self.stats.inc_value(f'item_dropped_reasons_count/{reason}', spider=spider)