Python 如何将不同的scrapy spider结果输送到不同的表中
我在同一个文件中创建了一个web爬行器,可以从不同的网站上抓取数据。当我单独运行每个spider时,我可以成功地将刮取的数据从models.py文件管道传输到postgresql表中。但是,当我使用同时运行两个spider时,会创建每个spider的表,但由于某种原因,无法将数据刮入其中。我认为这可能与每次运行spider时调用已定义管道类的方式有关,但很难说清楚,因为文档并没有真正显示实现的内部内容。根据我提供的代码,我是否有正确的设置来将数据管道化到两个不同的表中 型号.pyPython 如何将不同的scrapy spider结果输送到不同的表中,python,postgresql,web-scraping,scrapy,twisted,Python,Postgresql,Web Scraping,Scrapy,Twisted,我在同一个文件中创建了一个web爬行器,可以从不同的网站上抓取数据。当我单独运行每个spider时,我可以成功地将刮取的数据从models.py文件管道传输到postgresql表中。但是,当我使用同时运行两个spider时,会创建每个spider的表,但由于某种原因,无法将数据刮入其中。我认为这可能与每次运行spider时调用已定义管道类的方式有关,但很难说清楚,因为文档并没有真正显示实现的内部内容。根据我提供的代码,我是否有正确的设置来将数据管道化到两个不同的表中 型号.py from sq
from sqlalchemy.orm import sessionmaker
from models import Tickets, Tickets3, db_connect, create_vs_tickets_table, create_tc_tickets_table
class ComparatorPipeline(object):
"""Price comparison pipeline for storing scraped items in the database"""
def __init__(self):
"""
Initializes database connection and sessionmaker.
Creates deals table.
"""
engine = db_connect()
create_vs_tickets_table(engine)
create_tc_tickets_table(engine)
self.Session = sessionmaker(bind=engine)
def process_item(self, item, spider):
"""Save tickets in the database.
This method is called for every item pipeline component.
"""
if spider.name == "comparator":
session = self.Session()
ticket = Tickets(**item)
try:
session.add(ticket)
session.commit()
except:
session.rollback()
raise
finally:
session.close()
return item
elif spider.name == "comparator3":
session = self.Session()
ticket3 = Tickets3(**item)
try:
session.add(ticket3)
session.commit()
except:
session.rollback()
raise
finally:
session.close()
return item
蜘蛛定义
import scrapy
import re
import json
from scrapy.crawler import CrawlerProcess
from scrapy import Request
from scrapy.contrib.spiders import CrawlSpider , Rule
from scrapy.selector import HtmlXPathSelector
from scrapy.selector import Selector
from scrapy.contrib.loader import ItemLoader
from scrapy.contrib.loader import XPathItemLoader
from scrapy.contrib.loader.processor import Join, MapCompose
from concert_comparator.items import ComparatorItem, ComparatorItem3
from urlparse import urljoin
from scrapy.crawler import CrawlerRunner
from twisted.internet import reactor, defer
from scrapy.utils.log import configure_logging
bandname = raw_input("Enter a bandname \n")
vs_url = "http://www.vividseats.com/concerts/" + bandname + "-tickets.html"
tc_url = "https://www.ticketcity.com/concerts/" + bandname + "-tickets.html"
class MySpider(CrawlSpider):
handle_httpstatus_list = [416]
name = 'comparator'
allowed_domains = ["www.vividseats.com"]
start_urls = [vs_url]
tickets_list_xpath = './/*[@itemtype="http://schema.org/Event"]'
def parse_json(self, response):
loader = response.meta['loader']
jsonresponse = json.loads(response.body_as_unicode())
ticket_info = jsonresponse.get('tickets')
price_list = [i.get('p') for i in ticket_info]
if len(price_list) > 0:
str_Price = str(price_list[0])
ticketPrice = unicode(str_Price, "utf-8")
loader.add_value('ticketPrice', ticketPrice)
else:
ticketPrice = unicode("sold out", "utf-8")
loader.add_value('ticketPrice', ticketPrice)
return loader.load_item()
def parse_price(self, response):
loader = response.meta['loader']
ticketsLink = loader.get_output_value("ticketsLink")
json_id_list= re.findall(r"(\d+)[^-]*$", ticketsLink)
json_id= "".join(json_id_list)
json_url = "http://www.vividseats.com/javascript/tickets.shtml?productionId=" + json_id
yield scrapy.Request(json_url, meta={'loader': loader}, callback = self.parse_json, dont_filter = True)
def parse(self, response):
"""
# """
selector = HtmlXPathSelector(response)
# iterate over tickets
for ticket in selector.select(self.tickets_list_xpath):
loader = XPathItemLoader(ComparatorItem(), selector=ticket)
# define loader
loader.default_input_processor = MapCompose(unicode.strip)
loader.default_output_processor = Join()
# iterate over fields and add xpaths to the loader
loader.add_xpath('eventName' , './/*[@class="productionsEvent"]/text()')
loader.add_xpath('eventLocation' , './/*[@class = "productionsVenue"]/span[@itemprop = "name"]/text()')
loader.add_xpath('ticketsLink' , './/*/a[@class = "btn btn-primary"]/@href')
loader.add_xpath('eventDate' , './/*[@class = "productionsDate"]/text()')
loader.add_xpath('eventCity' , './/*[@class = "productionsVenue"]/span[@itemprop = "address"]/span[@itemprop = "addressLocality"]/text()')
loader.add_xpath('eventState' , './/*[@class = "productionsVenue"]/span[@itemprop = "address"]/span[@itemprop = "addressRegion"]/text()')
loader.add_xpath('eventTime' , './/*[@class = "productionsTime"]/text()')
print "Here is ticket link \n" + loader.get_output_value("ticketsLink")
#sel.xpath("//span[@id='PractitionerDetails1_Label4']/text()").extract()
ticketsURL = "concerts/" + bandname + "-tickets/" + bandname + "-" + loader.get_output_value("ticketsLink")
ticketsURL = urljoin(response.url, ticketsURL)
yield scrapy.Request(ticketsURL, meta={'loader': loader}, callback = self.parse_price, dont_filter = True)
class MySpider3(CrawlSpider):
handle_httpstatus_list = [416]
name = 'comparator3'
allowed_domains = ["www.ticketcity.com"]
start_urls = [tc_url]
tickets_list_xpath = './/div[@class = "vevent"]'
def parse_json(self, response):
loader = response.meta['loader']
jsonresponse = json.loads(response.body_as_unicode())
ticket_info = jsonresponse.get('B')
price_list = [i.get('P') for i in ticket_info]
if len(price_list) > 0:
str_Price = str(price_list[0])
ticketPrice = unicode(str_Price, "utf-8")
loader.add_value('ticketPrice', ticketPrice)
else:
ticketPrice = unicode("sold out", "utf-8")
loader.add_value('ticketPrice', ticketPrice)
return loader.load_item()
def parse_price(self, response):
print "parse price function entered \n"
loader = response.meta['loader']
event_City = response.xpath('.//span[@itemprop="addressLocality"]/text()').extract()
eventCity = ''.join(event_City)
loader.add_value('eventCity' , eventCity)
event_State = response.xpath('.//span[@itemprop="addressRegion"]/text()').extract()
eventState = ''.join(event_State)
loader.add_value('eventState' , eventState)
event_Date = response.xpath('.//span[@class="event_datetime"]/text()').extract()
eventDate = ''.join(event_Date)
loader.add_value('eventDate' , eventDate)
ticketsLink = loader.get_output_value("ticketsLink")
json_id_list= re.findall(r"(\d+)[^-]*$", ticketsLink)
json_id= "".join(json_id_list)
json_url = "https://www.ticketcity.com/Catalog/public/v1/events/" + json_id + "/ticketblocks?P=0,99999999&q=0&per_page=250&page=1&sort=p.asc&f.t=s&_=1436642392938"
yield scrapy.Request(json_url, meta={'loader': loader}, callback = self.parse_json, dont_filter = True)
def parse(self, response):
"""
# """
selector = HtmlXPathSelector(response)
# iterate over tickets
for ticket in selector.select(self.tickets_list_xpath):
loader = XPathItemLoader(ComparatorItem(), selector=ticket)
# define loader
loader.default_input_processor = MapCompose(unicode.strip)
loader.default_output_processor = Join()
# iterate over fields and add xpaths to the loader
loader.add_xpath('eventName' , './/span[@class="summary listingEventName"]/text()')
loader.add_xpath('eventLocation' , './/div[@class="divVenue location"]/text()')
loader.add_xpath('ticketsLink' , './/a[@class="divEventDetails url"]/@href')
#loader.add_xpath('eventDateTime' , '//div[@id="divEventDate"]/@title') #datetime type
#loader.add_xpath('eventTime' , './/*[@class = "productionsTime"]/text()')
print "Here is ticket link \n" + loader.get_output_value("ticketsLink")
#sel.xpath("//span[@id='PractitionerDetails1_Label4']/text()").extract()
ticketsURL = "https://www.ticketcity.com/" + loader.get_output_value("ticketsLink")
ticketsURL = urljoin(response.url, ticketsURL)
yield scrapy.Request(ticketsURL, meta={'loader': loader}, callback = self.parse_price, dont_filter = True)
configure_logging()
runner = CrawlerRunner()
@defer.inlineCallbacks
def crawl():
yield runner.crawl(MySpider)
yield runner.crawl(MySpider3)
reactor.stop()
crawl()
reactor.run()
我不太理解您的问题,但在我看来,您有两个表,两个不同的类代表一个数据库条目(Tickets和Tickets3),还有一个管道将它们保存到数据库中
调用这条管道时,将使用两个spider的结果。为什么不在
process\u项
函数中使用spider
变量来区分不同的元素?spider有一个名称,因此您可以使用该工具查看是哪个spider将项目发送到处理。向spider添加自定义设置
class MySpider(CrawlSpider):
custom_settings = {
'ITEM_PIPELINES': {
'pipelines.ComparatorPipeline': 400
}
}
handle_httpstatus_list = [416]
并禁用设置中的项目管道列表
# ITEM_PIPELINES = {
# }
从我的理解来看,问题在于,因为每次刮取一个站点的所有数据时,都会调用ComparatorPipeline类,所以它不知道如何区分它当前拥有的spider结果。我尝试在process_item方法中使用一个控制结构,它将检查爬行器的名称,然后根据该条件将该项添加到会话中,但是当我尝试时,两个表都没有创建。我想我需要一种方法来在每次调用管道类时添加每个spider的项。更新实际上,我已经能够在process_item方法中获得一条控制语句,但只有在我自己运行第一个spider时。当我使用scapy文档中的一个接一个地运行它们时,它不会写入其中任何一个。