Python 详解通过Scrapy框架实现爬取百度新冠疫情数

编辑: admin 分类: python 发布时间: 2021-12-03 来源:互联网
目录
  • 前言
  • 环境部署
    • 插件推荐
    • 爬虫目标
    • 项目创建
    • webdriver部署
  • 项目代码
    • Item定义
    • 中间件定义
    • 定义爬虫
    • pipeline输出结果文本
    • 配置文件改动
  • 验证结果
    • 总结

      前言

      闲来无聊,写了一个爬虫程序获取百度疫情数据。申明一下,研究而已。而且页面应该会进程做反爬处理,可能需要调整对应xpath。

      Github仓库地址:代码仓库

      本文主要使用的是scrapy框架。

      环境部署

      主要简单推荐一下

      插件推荐

      这里先推荐一个Google Chrome的扩展插件xpath helper,可以验证xpath语法是不是正确。

      爬虫目标

      需要爬取的页面:实时更新:新型冠状病毒肺炎疫情地图

      主要爬取的目标选取了全国的数据以及各个身份的数据。

      项目创建

      使用scrapy命令创建项目

      scrapy startproject yqsj

      webdriver部署

      这里就不重新讲一遍了,可以参考我这篇文章的部署方法:Python 详解通过Scrapy框架实现爬取CSDN全站热榜标题热词流程

      项目代码

      开始撸代码,看一下百度疫情省份数据的问题。

      页面需要点击展开全部span。所以在提取页面源码的时候需要模拟浏览器打开后,点击该按钮。所以按照这个方向,我们一步步来。

      Item定义

      定义两个类YqsjProvinceItem和YqsjChinaItem,分别定义国内省份数据和国内数据。

      # Define here the models for your scraped items
      #
      # See documentation in:
      # https://docs.scrapy.org/en/latest/topics/items.html
       
      import scrapy
       
       
      class YqsjProvinceItem(scrapy.Item):
          # define the fields for your item here like:
          # name = scrapy.Field()
          location = scrapy.Field()
          new = scrapy.Field()
          exist = scrapy.Field()
          total = scrapy.Field()
          cure = scrapy.Field()
          dead = scrapy.Field()
       
       
      class YqsjChinaItem(scrapy.Item):
          # define the fields for your item here like:
          # name = scrapy.Field()
          # 现有确诊
          exist_diagnosis = scrapy.Field()
          # 无症状
          asymptomatic = scrapy.Field()
          # 现有疑似
          exist_suspecte = scrapy.Field()
          # 现有重症
          exist_severe = scrapy.Field()
          # 累计确诊
          cumulative_diagnosis = scrapy.Field()
          # 境外输入
          overseas_input = scrapy.Field()
          # 累计治愈
          cumulative_cure = scrapy.Field()
          # 累计死亡
          cumulative_dead = scrapy.Field()

      中间件定义

      需要打开页面后点击一下展开全部。

      完整代码

      # Define here the models for your spider middleware
      #
      # See documentation in:
      # https://docs.scrapy.org/en/latest/topics/spider-middleware.html
       
      from scrapy import signals
       
      # useful for handling different item types with a single interface
      from itemadapter import is_item, ItemAdapter
      from scrapy.http import HtmlResponse
      from selenium.common.exceptions import TimeoutException
      from selenium.webdriver import ActionChains
      import time
       
       
      class YqsjSpiderMiddleware:
          # Not all methods need to be defined. If a method is not defined,
          # scrapy acts as if the spider middleware does not modify the
          # passed objects.
       
          @classmethod
          def from_crawler(cls, crawler):
              # This method is used by Scrapy to create your spiders.
              s = cls()
              crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
              return s
       
          def process_spider_input(self, response, spider):
              # Called for each response that goes through the spider
              # middleware and into the spider.
       
              # Should return None or raise an exception.
              return None
       
          def process_spider_output(self, response, result, spider):
              # Called with the results returned from the Spider, after
              # it has processed the response.
       
              # Must return an iterable of Request, or item objects.
              for i in result:
                  yield i
       
          def process_spider_exception(self, response, exception, spider):
              # Called when a spider or process_spider_input() method
              # (from other spider middleware) raises an exception.
       
              # Should return either None or an iterable of Request or item objects.
              pass
       
          def process_start_requests(self, start_requests, spider):
              # Called with the start requests of the spider, and works
              # similarly to the process_spider_output() method, except
              # that it doesn't have a response associated.
       
              # Must return only requests (not items).
              for r in start_requests:
                  yield r
       
          def spider_opened(self, spider):
              spider.logger.info('Spider opened: %s' % spider.name)
       
       
      class YqsjDownloaderMiddleware:
          # Not all methods need to be defined. If a method is not defined,
          # scrapy acts as if the downloader middleware does not modify the
          # passed objects.
       
          @classmethod
          def from_crawler(cls, crawler):
              # This method is used by Scrapy to create your spiders.
              s = cls()
              crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
              return s
       
          def process_request(self, request, spider):
              # Called for each request that goes through the downloader
              # middleware.
       
              # Must either:
              # - return None: continue processing this request
              # - or return a Response object
              # - or return a Request object
              # - or raise IgnoreRequest: process_exception() methods of
              #   installed downloader middleware will be called
              # return None
              try:
                  spider.browser.get(request.url)
                  spider.browser.maximize_window()
                  time.sleep(2)
                  spider.browser.find_element_by_xpath("//*[@id='nationTable']/div/span").click()
                  # ActionChains(spider.browser).click(searchButtonElement)
                  time.sleep(5)
                  return HtmlResponse(url=spider.browser.current_url, body=spider.browser.page_source,
                                      encoding="utf-8", request=request)
              except TimeoutException as e:
                  print('超时异常:{}'.format(e))
                  spider.browser.execute_script('window.stop()')
              finally:
                  spider.browser.close()
       
          def process_response(self, request, response, spider):
              # Called with the response returned from the downloader.
       
              # Must either;
              # - return a Response object
              # - return a Request object
              # - or raise IgnoreRequest
              return response
       
          def process_exception(self, request, exception, spider):
              # Called when a download handler or a process_request()
              # (from other downloader middleware) raises an exception.
       
              # Must either:
              # - return None: continue processing this exception
              # - return a Response object: stops process_exception() chain
              # - return a Request object: stops process_exception() chain
              pass
       
          def spider_opened(self, spider):
              spider.logger.info('Spider opened: %s' % spider.name)

      定义爬虫

      分别获取国内疫情数据以及省份疫情数据。完整代码:

      #!/usr/bin/env python
      # -*- coding: utf-8 -*-
      # @Time    : 2021/11/7 22:05
      # @Author  : 至尊宝
      # @Site    : 
      # @File    : baidu_yq.py
       
      import scrapy
      from selenium import webdriver
      from selenium.webdriver.chrome.options import Options
       
      from yqsj.items import YqsjChinaItem, YqsjProvinceItem
       
       
      class YqsjSpider(scrapy.Spider):
          name = 'yqsj'
          # allowed_domains = ['blog.csdn.net']
          start_urls = ['https://voice.baidu.com/act/newpneumonia/newpneumonia#tab0']
          china_xpath = "//div[contains(@class, 'VirusSummarySix_1-1-317_2ZJJBJ')]/text()"
          province_xpath = "//*[@id='nationTable']/table/tbody/tr[{}]/td/text()"
          province_xpath_1 = "//*[@id='nationTable']/table/tbody/tr[{}]/td/div/span/text()"
       
          def __init__(self):
              chrome_options = Options()
              chrome_options.add_argument('--headless')  # 使用无头谷歌浏览器模式
              chrome_options.add_argument('--disable-gpu')
              chrome_options.add_argument('--no-sandbox')
              self.browser = webdriver.Chrome(chrome_options=chrome_options,
                                              executable_path="E:\\chromedriver_win32\\chromedriver.exe")
              self.browser.set_page_load_timeout(30)
       
          def parse(self, response, **kwargs):
              country_info = response.xpath(self.china_xpath)
              yq_china = YqsjChinaItem()
              yq_china['exist_diagnosis'] = country_info[0].get()
              yq_china['asymptomatic'] = country_info[1].get()
              yq_china['exist_suspecte'] = country_info[2].get()
              yq_china['exist_severe'] = country_info[3].get()
              yq_china['cumulative_diagnosis'] = country_info[4].get()
              yq_china['overseas_input'] = country_info[5].get()
              yq_china['cumulative_cure'] = country_info[6].get()
              yq_china['cumulative_dead'] = country_info[7].get()
              yield yq_china
              
              # 遍历35个地区
              for x in range(1, 35):
                  path = self.province_xpath.format(x)
                  path1 = self.province_xpath_1.format(x)
                  province_info = response.xpath(path)
                  province_name = response.xpath(path1)
                  yq_province = YqsjProvinceItem()
                  yq_province['location'] = province_name.get()
                  yq_province['new'] = province_info[0].get()
                  yq_province['exist'] = province_info[1].get()
                  yq_province['total'] = province_info[2].get()
                  yq_province['cure'] = province_info[3].get()
                  yq_province['dead'] = province_info[4].get()
                  yield yq_province

      pipeline输出结果文本

      将结果按照一定的文本格式输出出来。完整代码:

      # Define your item pipelines here
      #
      # Don't forget to add your pipeline to the ITEM_PIPELINES setting
      # See: https://docs.scrapy.org/en/latest/topics/item-pipeline.html
       
       
      # useful for handling different item types with a single interface
      from itemadapter import ItemAdapter
       
      from yqsj.items import YqsjChinaItem, YqsjProvinceItem
       
       
      class YqsjPipeline:
          def __init__(self):
              self.file = open('result.txt', 'w', encoding='utf-8')
       
          def process_item(self, item, spider):
              if isinstance(item, YqsjChinaItem):
                  self.file.write(
                      "国内疫情\n现有确诊\t{}\n无症状\t{}\n现有疑似\t{}\n现有重症\t{}\n累计确诊\t{}\n境外输入\t{}\n累计治愈\t{}\n累计死亡\t{}\n".format(
                          item['exist_diagnosis'],
                          item['asymptomatic'],
                          item['exist_suspecte'],
                          item['exist_severe'],
                          item['cumulative_diagnosis'],
                          item['overseas_input'],
                          item['cumulative_cure'],
                          item['cumulative_dead']))
              if isinstance(item, YqsjProvinceItem):
                  self.file.write(
                      "省份:{}\t新增:{}\t现有:{}\t累计:{}\t治愈:{}\t死亡:{}\n".format(
                          item['location'],
                          item['new'],
                          item['exist'],
                          item['total'],
                          item['cure'],
                          item['dead']))
              return item
       
          def close_spider(self, spider):
              self.file.close()

      配置文件改动

      直接参考,自行调整:

      # Scrapy settings for yqsj project
      #
      # For simplicity, this file contains only settings considered important or
      # commonly used. You can find more settings consulting the documentation:
      #
      #     https://docs.scrapy.org/en/latest/topics/settings.html
      #     https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
      #     https://docs.scrapy.org/en/latest/topics/spider-middleware.html
       
      BOT_NAME = 'yqsj'
       
      SPIDER_MODULES = ['yqsj.spiders']
      NEWSPIDER_MODULE = 'yqsj.spiders'
       
       
      # Crawl responsibly by identifying yourself (and your website) on the user-agent
      #USER_AGENT = 'yqsj (+http://www.yourdomain.com)'
      USER_AGENT = 'Mozilla/5.0'
       
      # Obey robots.txt rules
      ROBOTSTXT_OBEY = False
       
      # Configure maximum concurrent requests performed by Scrapy (default: 16)
      #CONCURRENT_REQUESTS = 32
       
      # Configure a delay for requests for the same website (default: 0)
      # See https://docs.scrapy.org/en/latest/topics/settings.html#download-delay
      # See also autothrottle settings and docs
      #DOWNLOAD_DELAY = 3
      # The download delay setting will honor only one of:
      #CONCURRENT_REQUESTS_PER_DOMAIN = 16
      #CONCURRENT_REQUESTS_PER_IP = 16
       
      # Disable cookies (enabled by default)
      COOKIES_ENABLED = False
       
      # Disable Telnet Console (enabled by default)
      #TELNETCONSOLE_ENABLED = False
       
      # Override the default request headers:
      DEFAULT_REQUEST_HEADERS = {
          'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
          'Accept-Language': 'en',
          'User-Agent': 'Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.94 Safari/537.36'
      }
       
      # Enable or disable spider middlewares
      # See https://docs.scrapy.org/en/latest/topics/spider-middleware.html
      SPIDER_MIDDLEWARES = {
         'yqsj.middlewares.YqsjSpiderMiddleware': 543,
      }
       
      # Enable or disable downloader middlewares
      # See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
      DOWNLOADER_MIDDLEWARES = {
         'yqsj.middlewares.YqsjDownloaderMiddleware': 543,
      }
       
      # Enable or disable extensions
      # See https://docs.scrapy.org/en/latest/topics/extensions.html
      #EXTENSIONS = {
      #    'scrapy.extensions.telnet.TelnetConsole': None,
      #}
       
      # Configure item pipelines
      # See https://docs.scrapy.org/en/latest/topics/item-pipeline.html
      ITEM_PIPELINES = {
         'yqsj.pipelines.YqsjPipeline': 300,
      }
       
      # Enable and configure the AutoThrottle extension (disabled by default)
      # See https://docs.scrapy.org/en/latest/topics/autothrottle.html
      #AUTOTHROTTLE_ENABLED = True
      # The initial download delay
      #AUTOTHROTTLE_START_DELAY = 5
      # The maximum download delay to be set in case of high latencies
      #AUTOTHROTTLE_MAX_DELAY = 60
      # The average number of requests Scrapy should be sending in parallel to
      # each remote server
      #AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0
      # Enable showing throttling stats for every response received:
      #AUTOTHROTTLE_DEBUG = False
       
      # Enable and configure HTTP caching (disabled by default)
      # See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings
      #HTTPCACHE_ENABLED = True
      #HTTPCACHE_EXPIRATION_SECS = 0
      #HTTPCACHE_DIR = 'httpcache'
      #HTTPCACHE_IGNORE_HTTP_CODES = []
      #HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage'

      验证结果

      看看结果文件

      总结

      emmmm,闲着无聊,写着玩,没啥好总结的。

      分享:

      修心,亦是修行之一。顺境修力,逆境修心,缺一不可。 ——《剑来》

      如果本文对你有作用的话,不要吝啬你的赞,谢谢。

      以上就是Python 详解通过Scrapy框架实现爬取百度新冠疫情数据流程的详细内容,更多关于Python Scrapy框架的资料请关注hwidc其它相关文章!

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