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我正在開發一個Scrapy項目,我在其上編寫了一個DOWNLOADER MIDDLEWARE以避免向已經在數據庫中的URL發出請求。Scrapy - 獲取內部蜘蛛變量下載MIDDLEWARE __init__
DOWNLOADER_MIDDLEWARES = {
'imobotS.utilities.RandomUserAgentMiddleware': 400,
'imobotS.utilities.DupFilterMiddleware': 500,
'scrapy.contrib.downloadermiddleware.useragent.UserAgentMiddleware': None,
}
的想法是連接和__init__負載當前存儲在數據庫中的所有URL的不同名單,並提高IgnoreRequests如果刮出項目已經是DB。
class DuplicateFilterMiddleware(object):
def __init__(self):
connection = pymongo.Connection('localhost', 12345)
self.db = connection['my_db']
self.db.authenticate('scott', '*****')
self.url_set = self.db.ad.find({'site': 'WEBSITE_NAME'}).distinct('url')
def process_request(self, request, spider):
print "%s - process Request URL: %s" % (spider._site_name, request.url)
if request.url in self.url_set:
raise IgnoreRequest("Duplicate --db-- item found: %s" % request.url)
else:
return None
所以,我想通過限制對WEBSITE_NAME初始化定義的URL_LIST,有沒有辦法來識別下載中間件__init__方法中目前蜘蛛的名字嗎?