def _get_last_ts(self):
"""Returns a datetime object"""
if os.path.exists(self.last_seen_filename):
with open(self.last_seen_filename) as f:
f.seek(0)
try:
return utils.convert_to_datetime(f.read().strip())
except ValueError:
return None
return None
def process_item(self, item, spider):
# inject source name
item['source'] = spider.name
item_date = utils.convert_to_datetime(item['date'])
# if crawler launched for the first time - get first item's date as
# last_ts; else take last launch time as starting point
if not self.last_ts:
self.last_ts = (item_date if not spider.last_ts else spider.last_ts)
# first launch -> save all items found
if not spider.last_ts:
return item
# if last_ts exists -> any item older than last crawl time is ignored
if item_date <= spider.last_ts:
raise exceptions.DropItem(
"Item %s date is older than last crawled" % item)
# in case posts can be updated -> check that last ts is maximum
if (self.last_ts < item_date):
self.last_ts = item_date
return item
