Python 详解通过Scrapy框架实现爬取百度新冠疫情数据流程

Vevina ·
更新时间:2024-09-21
· 171 次阅读

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》

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