Python 详解通过Scrapy框架实现爬取百度新冠疫情数据流程

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。

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