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我有蜘蛛處理鏈中的請求使用meta
產生具有來自多個請求的數據的項目。 我用來生成請求的方式是在第一次調用解析函數時啓動所有請求,但是,如果我有太多的鏈接來請求並不是所有的請求都被調度,並且我最終沒有得到所需的一切。Scrapy蜘蛛沒有收到spider_idle信號
爲了解決這個問題,我試圖讓蜘蛛請求5種產品,當蜘蛛閒置時(通過連接from_crawler
中的信號)再次請求蜘蛛。 問題是,因爲我的代碼是現在,spider_idle不運行request
函數和蜘蛛立即關閉。就好像蜘蛛不會閒置一樣。
下面是一些代碼:
class ProductSpider(scrapy.Spider):
def __init__(self, *args, **kwargs):
super(ProductSpider, self).__init__(*args, **kwargs)
self.parsed_data = []
self.header = {}
f = open('file.csv', 'r')
f_data = [[x.strip()] for x in f]
count=1
first = 'smth'
for product in f_data:
if first != '':
header = product[0].split(';')
for each in range(len(header[1:])):
self.header[header[each+1]] = each+1
first = ''
else:
product = product[0].split(';')
product.append(count)
count+=1
self.parsed_data.append(product)
f.close()
@classmethod
def from_crawler(cls, crawler, *args, **kwargs):
spider = super(ProductSpider, cls).from_crawler(crawler, *args, **kwargs)
crawler.signals.connect(spider.request, signal=signals.spider_idle)
return spider
name = 'products'
allowed_domains = [domains]
handle_httpstatus_list = [400, 404, 403, 503, 504]
start_urls = [start]
def next_link(self,response):
product = response.meta['product']
there_is_next = False
for each in range(response.meta['each']+1, len(product)-1):
if product[each] != '':
there_is_next = True
yield scrapy.Request(product[each], callback=response.meta['func_dict'][each], meta={'func_dict': response.meta['func_dict'],'product':product,'each':each,'price_dict':response.meta['price_dict'], 'item':response.meta['item']}, dont_filter=True)
break
if not there_is_next:
item = response.meta['item']
item['prices'] = response.meta['price_dict']
yield item
#[...] chain parsing functions for each request
def get_products(self):
products = []
data = self.parsed_data
for each in range(5):
if data:
products.append(data.pop())
return products
def request(self):
item = Header()
item['first'] = True
item['sellers'] = self.header
yield item
func_dict = {parsing_functions_for_every_site}
products = self.get_products()
if not products:
return
for product in products:
item = Product()
price_dict = {1:product[1]}
item['name'] = product[0]
item['order'] = product[-1]
for each in range(2, len(product)-1):
if product[each] != '':
#print each, func_dict, product[each]
yield scrapy.Request(product[each], callback=func_dict[each],
meta={'func_dict': func_dict,'product':product,
'each':each,'price_dict':price_dict, 'item':item})
break
raise DontCloseSpider
def parse(self, response=None):
pass
好吧!謝謝,它似乎工作:)正常的scrapy.Request()和self.crawler.engine.crawl之間有什麼區別? – AimiHat
沒有真正的區別,唯一的一點是'scrapy'處理回調方法,將它們添加到請求隊列中而不會注意到,並且'self.crawler.engine..'你明確地添加請求 – eLRuLL