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個(gè)人ScrapyDemo項(xiàng)目地址

python環(huán)境安裝

• win下安裝：
  • python：下載python安裝包直接安裝即可
  • pip： easy_install pip
• mac下安裝：
  • python：mac下自帶python2.7
  • pip： easy_install pip
• centos7下安裝：
  • python：centos7下自帶python2.7
  • pip： easy_install pip

scrapy 安裝

pip install Scrapy

創(chuàng)建項(xiàng)目

scrapy startproject <project_name>

創(chuàng)建爬蟲(chóng)

scrapy genspider <spider_name> <host_name>

在文件夾根目錄創(chuàng)建 requirements.txt文件并加入需要的組件浮定，例如：

Scrapy==1.5.0
beautifulsoup4==4.6.0
requests==2.18.4

項(xiàng)目環(huán)境搭建

pip install -r requirements.txt

運(yùn)行單個(gè)爬蟲(chóng)

scrapy crawl <spider_name>

運(yùn)行多個(gè)爬蟲(chóng)（Scrapy本身并不支持命令行直接運(yùn)行多個(gè)Spiders降盹，創(chuàng)建一個(gè)新的python文件加入如下內(nèi)容運(yùn)行此python文件便可）（需按需更改）

# -*- coding: utf-8 -*-
import sys
    from scrapy.crawler import CrawlerProcess
from scrapy.utils.project import get_project_settings
from ScrapyDemo.spiders.news_estadao import EstadaoSpider
from ScrapyDemo.spiders.news_gazetaesportiva import DemoSpider
from ScrapyDemo.spiders.news_megacurioso import MegacuriosoSpider

if sys.getdefaultencoding != 'utf-8':
    reload(sys)
    sys.setdefaultencoding('utf-8')

process = CrawlerProcess(get_project_settings())
process.crawl(EstadaoSpider)
process.crawl(DemoSpider)
process.crawl(MegacuriosoSpider)
process.start()

啟用pipelines用于處理結(jié)果

• 打開(kāi)settings.py文件在ITEM_PIPELINES選項(xiàng)下加入peline并賦值彤敛，0-1000，數(shù)字越小越優(yōu)先

輸出單個(gè)spider運(yùn)行結(jié)果到文件

scrapy crawl demo -o /path/to/demo.json

多個(gè)spider的結(jié)果混合處理：

• 上面的運(yùn)行多個(gè)爬蟲(chóng)腳本并不能將多個(gè)spider的結(jié)果混合處理
• 因?yàn)闃I(yè)務(wù)需要，只可退而求其次

  • 思路：借助commands庫(kù)運(yùn)行l(wèi)inux命令順序運(yùn)行并輸出結(jié)果到文件毙替，最后讀取文件內(nèi)容解析為對(duì)象進(jìn)行混合處理

  • 代碼（需按需更改）：

    #!/usr/bin/env python
    # encoding: utf-8
    import commands
    
    def test():
      result = []
      try:
          commands.getoutput("echo '' > /path/to/megacurioso.json") #清空上次運(yùn)行結(jié)果
          commands.getoutput("scrapy crawl demo -o /path/to/demo.json") # 運(yùn)行結(jié)果并輸出
          result = json.loads(commands.getoutput("cat /path/to/megacurioso.json")) # 獲取運(yùn)行結(jié)果
      except:
          print "Get megacurioso error."
      return result
    

解決結(jié)果爬蟲(chóng)信息亂碼問(wèn)題：

• 在有亂碼問(wèn)題python文件頂部加入如下代碼：

  if sys.getdefaultencoding != 'utf-8':
    reload(sys)
    sys.setdefaultencoding('utf-8')
  

爬蟲(chóng)示例叉谜，也可以使用文頂給出的github鏈接：

• item示例(items.py)：

  # -*- coding: utf-8 -*-
  
  # Define here the models for your scraped items
  #
  # See documentation in:
  # https://doc.scrapy.org/en/latest/topics/items.html
  
  import scrapy
  
  
  class ScrapydemoItem(scrapy.Item):
      title = scrapy.Field()
      imageUrl = scrapy.Field()
      des = scrapy.Field()
      source = scrapy.Field()
      actionUrl = scrapy.Field()
      contentType = scrapy.Field()
      itemType = scrapy.Field()
      createTime = scrapy.Field()
      country = scrapy.Field()
      headUrl = scrapy.Field()
      pass
  

• pipelines示例（pipelines.py）：

  # -*- coding: utf-8 -*-
  
  # Define your item pipelines here
  #
  # Don't forget to add your pipeline to the ITEM_PIPELINES setting
  # See: https://doc.scrapy.org/en/latest/topics/item-pipeline.html
  from ScrapyDemo.items import ScrapydemoItem
  import json
  
  
  class ScrapydemoPipeline(object):
      DATA_LIST_NEWS = []
  
      def open_spider(self, spider):
          DATA_LIST_NEWS = []
          print 'Spider start.'
  
      def process_item(self, item, spider):
          if isinstance(item, ScrapydemoItem):
              self.DATA_LIST_NEWS.append(dict(item))
          return item
  
      def close_spider(self, spider):
          print json.dumps(self.DATA_LIST_NEWS)
          print 'Spider end.'
  

• spider示例(demo.py)：

      # -*- coding: utf-8 -*-
      import scrapy
      from ScrapyDemo.items import ScrapydemoItem
  
  
      class DemoSpider(scrapy.Spider):
          name = 'news_gazetaesportiva'
          allowed_domains = ['www.gazetaesportiva.com']
          start_urls = ['https://www.gazetaesportiva.com/noticias/']
          headers = {
              'accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8',
              'accept-language': 'zh-CN,zh;q=0.9,en-US;q=0.8,en;q=0.7',
              'cache-control': 'max-age=0',
              'upgrade-insecure-requests': '1',
              'User-agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.139 Safari/537.36'
          }
  
          def parse(self, response):
              print('Start parse.')
              for element in response.xpath('//article'):
                  title = element.xpath(".//h3[@class='entry-title no-margin']/a/text()").extract_first()
                  imageUrl = [element.xpath(".//img[@class='medias-object wp-post-image']/@src").extract_first()]
                  des = element.xpath(".//div[@class='entry-content space']/text()").extract_first()
                  source = 'gazeta'
                  actionUrl = element.xpath(".//a[@class='blog-image']/@href").extract_first()
                  contentType = ''
                  itemType = ''
                  createTime = element.xpath(".//small[@class='updated']/text()").extract_first()
                  country = 'PZ'
                  headUrl = ''
                  if title is not None and title != "" and actionUrl is not None and actionUrl != "" and imageUrl is not None and imageUrl != "":
                      item = ScrapydemoItem()
                      item['title'] = title
                      item['imageUrl'] = imageUrl
                      item['des'] = des
                      item['source'] = source
                      item['actionUrl'] = actionUrl
                      item['contentType'] = contentType
                      item['itemType'] = itemType
                      item['createTime'] = createTime
                      item['country'] = country
                      item['headUrl'] = headUrl
                      yield item
              print('End parse.')
  

• 代碼個(gè)人理解：

  • settings可配置公共配置及配置pipelines對(duì)spiders結(jié)果進(jìn)行匯總，例如(后面的數(shù)值越大優(yōu)先級(jí)越低痊臭，取值0-1000)：

    ITEM_PIPELINES = {
        'DemoScrapy.pipelines.ScrapydemoPipeline': 300,
    }
    

  • 配置pipelines后命令行運(yùn)行spiders是會(huì)先運(yùn)行open_spider方法哮肚，然后每個(gè)結(jié)果解析時(shí)運(yùn)行process_item方法，最后spider結(jié)束時(shí)運(yùn)行close_spider方法

  • items文件是用來(lái)配置描述結(jié)果對(duì)象的

  • spiders文件夾里根據(jù)命令行創(chuàng)建的spiders文件配置需要抓取的數(shù)據(jù)的網(wǎng)頁(yè)及需要偽裝的請(qǐng)求頭參數(shù)等广匙，抓取數(shù)據(jù)后數(shù)據(jù)結(jié)果進(jìn)入 parse方法進(jìn)行解析允趟，可使用xpath進(jìn)行解析。xpath的具體使用可參考前文給出的鏈接鸦致，個(gè)人進(jìn)行數(shù)據(jù)抓取前使用chrom定位標(biāo)簽潮剪，復(fù)制源碼后根據(jù)規(guī)則找到標(biāo)簽位置最后進(jìn)行規(guī)則匹配，因?yàn)槊看螖?shù)據(jù)規(guī)則匹配不可能一次性完成分唾，建議使用debug功能來(lái)進(jìn)行匹配抗碰，最后一次性完成規(guī)則書(shū)寫。

• pycharm下debug spiders：

  • 打開(kāi)pycharm后如果遇到部分插件無(wú)法安裝的情況可使用虛擬環(huán)境：

    
    
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  • debug運(yùn)行scrapy：

    
    
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    • 運(yùn)行到斷點(diǎn)后右擊選擇 Evaluate Expresion

      
      
      如此便可隨意運(yùn)行代碼查看執(zhí)行結(jié)果