【问题标题】:Scrapy spider results can't be pipelined into database when ran from a script从脚本运行时,Scrapy spider 结果无法通过管道传输到数据库中
【发布时间】:2015-10-15 14:17:00
【问题描述】:

我编写了一个 Scrapy 蜘蛛,我试图从另一个目录中的 python 脚本运行它。我在docs 中使用的代码似乎在运行蜘蛛,但是当我检查 postgresql 表时,它还没有被创建。只有当我使用 scrapy crawl 命令时,蜘蛛才会正确地处理抓取的数据。我尝试将脚本放在scrapy项目正上方的目录中,并且与配置文件位于同一目录中,但似乎都没有创建表。

下面是脚本代码,后面是蜘蛛代码。我认为问题涉及应该放置脚本的目录和/或我在蜘蛛文件中使用的代码,以使蜘蛛能够从脚本运行,但我不确定。脚本中调用的函数是否存在问题,或者是否需要在设置文件中更改某些内容?如有需要,我可以提供管道文件的代码,谢谢。

脚本文件(只有 3 行)

from ticket_city_scraper import *
from ticket_city_scraper.spiders import tc_spider 

tc_spider.spiderCrawl()

蜘蛛文件

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 ticket_city_scraper.items import ComparatorItem
from urlparse import urljoin

from scrapy.utils.project import get_project_settings
from scrapy.crawler import CrawlerRunner
from twisted.internet import reactor, defer
from scrapy.utils.log import configure_logging



bandname = raw_input("Enter bandname\n")
tc_url = "https://www.ticketcity.com/concerts/" + bandname + "-tickets.html"  

class MySpider3(CrawlSpider):
    handle_httpstatus_list = [416]
    name = 'comparator'
    allowed_domains = ["www.ticketcity.com"]

    start_urls = [tc_url]
    tickets_list_xpath = './/div[@class = "vevent"]'
    def create_link(self, bandname):
        tc_url = "https://www.ticketcity.com/concerts/" + bandname + "-tickets.html"  
        self.start_urls = [tc_url]
        #return 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)

def spiderCrawl():
   process = CrawlerProcess({
    'USER_AGENT': 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)'
   })
   process.crawl(MySpider3)
   process.start()

【问题讨论】:

  • 没有太多调查(因此评论),当我看到这种错误时,我发现this post's advice很有帮助。
  • @Muttonchop 因此,我查看了该帖子并找到了建议进行此安装的答案: pip install service_identity - 错误消失了。实际上我认为这不是问题,因为结果仍然没有被输送到数据库中,所以我会修改帖子,谢谢你的链接。
  • 在您更新的帖子中,我没有看到您导入 CrawlerProcess。您是否在示例代码中遗漏了一些导入?
  • @Muttonchop 是的,我遗漏了一些导入。我刚刚更新了,谢谢。

标签: python postgresql sqlalchemy web-scraping scrapy


【解决方案1】:

这是因为您的设置对象只包含一个用户代理。您的项目设置决定了运行哪个管道。来自scrapy docs:

你可以 自动导入您的蜘蛛并将其名称传递给 CrawlerProcess,并使用 get_project_settings 获取 Settings 使用您的项目设置实例。

更多信息在这里http://doc.scrapy.org/en/latest/topics/practices.html

阅读比第一个例子更多的内容。

【讨论】:

    猜你喜欢
    • 2020-09-26
    • 2014-03-18
    • 2014-03-18
    • 2015-10-13
    • 2017-12-10
    • 2015-09-13
    • 1970-01-01
    • 1970-01-01
    • 2014-09-29
    相关资源
    最近更新 更多