爬虫第三部分综合案例

(1)第一步:内容介绍

(2)

 网易新闻的链接:https://news.163.com/

重点爬取五个板块的文字:国内,国际,军事,航空,无人机

需求:爬取基于文字的新闻数据

三步走

第一步:

新建项目
scrapy startproject wangyiPro
cd wangyiPro/

建立爬虫文件
scrapy genspider wangyi www.xxxx.com

第二步:组织数据结构和写爬虫文件

wangyi.py

import scrapy


class WangyiSpider(scrapy.Spider):
    name = 'wangyi'
    # allowed_domains = ['www.xxx.com']
    start_urls = ['https://news.163.com/']

    def parse(self, response):
        lis=response.xpath('//div[@class="ns_area list"]/ul/li')
        indexs=[3,4,6,7,8]
        li_list=[] #存储的就是国内,国际,军事,航空,无人机五个模块对应的li标签对象
        for index in indexs:
            li_list.append(lis[index])
        #获取四个板块中的链接和文字标题
        for li in li_list:
            url=li.xpath('./a/@href').extract_first()
            title=li.xpath('./a/text()').extract_first()
            print(url+":"+title)

在settings.py加上UA和robots设置

注意,在爬取数据量很小的时候可以不加,在某些网站上,这个案例就是这样

第三步:执行

scrapy crawl wangyi --nolog

结果:

(3)很多时间花费在解析数据上了

# -*- coding: utf-8 -*-
import scrapy


class WangyiSpider(scrapy.Spider):
    name = 'wangyi'
    # allowed_domains = ['www.xxx.com']
    start_urls = ['https://news.163.com/']

    def parse(self, response):
        lis=response.xpath('//div[@class="ns_area list"]/ul/li')
        indexs=[3,4,6,7,8]
        li_list=[] #存储的就是国内,国际,军事,航空,无人机五个模块对应的li标签对象
        for index in indexs:
            li_list.append(lis[index])
        #获取四个板块中的链接和文字标题
        for li in li_list:
            url=li.xpath('./a/@href').extract_first()
            title=li.xpath('./a/text()').extract_first()
            # print(url+":"+title)

            #对每一个板块对应的url发起请求，获取页面数据（标题，缩略图，关键字，发布时间，url）
            yield scrapy.Request(url=url,callback=self.parseSecond)
    def parseSecond(self,response):
        div_list=response.xpath('//div[@class="data_row news_article clearfix"]')
        print(len(div_list))
        for div in div_list:
            head=div.xpath('.//div[@class="news_title"]/h3/a/text()').extract_first()
            url=div.xpath('.//div[@class="news_title"]/h3/a/@href').extract_first()
            imgUrl=div.xpath('./a/img/@src').extract_first()
            publish_t=div.xpath('.//div[@class="news_tag"]/span/text()').extract_first()
            tag=div.xpath('.//div[@class="keywords"]/a/text()').extract()
            tag="".join(tag)

动态加载的数据拿不到,用selenium

(4)selenium的初步应用

# -*- coding: utf-8 -*-
import scrapy
from selenium import webdriver  #第一步,导包

#第二步,实例化浏览器,保证浏览器只能实例化一次

class WangyiSpider(scrapy.Spider):
    name = 'wangyi'
    # allowed_domains = ['www.xxx.com']
    start_urls = ['https://news.163.com/']
    def __init__(self):
        # 第二步,实例化一个浏览器对象(保证实例化一次)
        self.bro=webdriver.Chrome(executable_path='./chromedriver')
    def closed(self,spider):
        # 最后一步:必须在整个爬虫结束后,才关闭浏览器
        print('爬虫结束')
        self.bro.quit

    def parse(self, response):
        lis=response.xpath('//div[@class="ns_area list"]/ul/li')
        indexs=[3,4,6,7,8]
        li_list=[] #存储的就是国内,国际,军事,航空,无人机五个模块对应的li标签对象
        for index in indexs:
            li_list.append(lis[index])
        #获取四个板块中的链接和文字标题
        for li in li_list:
            url=li.xpath('./a/@href').extract_first()
            title=li.xpath('./a/text()').extract_first()
            # print(url+":"+title)

            #对每一个板块对应的url发起请求，获取页面数据（标题，缩略图，关键字，发布时间，url）
            yield scrapy.Request(url=url,callback=self.parseSecond)
    def parseSecond(self,response):
        div_list=response.xpath('//div[@class="data_row news_article clearfix"]')
        print(len(div_list))
        for div in div_list:
            head=div.xpath('.//div[@class="news_title"]/h3/a/text()').extract_first()
            url=div.xpath('.//div[@class="news_title"]/h3/a/@href').extract_first()
            imgUrl=div.xpath('./a/img/@src').extract_first()
            publish_t=div.xpath('.//div[@class="news_tag"]/span/text()').extract_first()
            tag=div.xpath('.//div[@class="keywords"]/a/text()').extract()
            tag="".join(tag)

(5)selenium在下载中间件中的配置2

 爬虫文件wangyi.py

# -*- coding: utf-8 -*-
import scrapy
from selenium import webdriver  #第一步,导包

#第二步,实例化浏览器,保证浏览器只能实例化一次

class WangyiSpider(scrapy.Spider):
    name = 'wangyi'
    # allowed_domains = ['www.xxx.com']
    start_urls = ['https://news.163.com/']
    def __init__(self):
        # 第二步,实例化一个浏览器对象(保证实例化一次)
        self.bro=webdriver.Chrome(executable_path='./wangyiPro/chromedriver.exe')
    def closed(self,spider):
        # 最后一步:必须在整个爬虫结束后,才关闭浏览器
        print('爬虫结束')
        self.bro.quit()

    def parse(self, response):
        lis=response.xpath('//div[@class="ns_area list"]/ul/li')
        indexs=[3,4,6,7,8]
        li_list=[] #存储的就是国内,国际,军事,航空,无人机五个模块对应的li标签对象
        for index in indexs:
            li_list.append(lis[index])
        #获取四个板块中的链接和文字标题
        for li in li_list:
            url=li.xpath('./a/@href').extract_first()
            title=li.xpath('./a/text()').extract_first()
            # print(url+":"+title)

            #对每一个板块对应的url发起请求，获取页面数据（标题，缩略图，关键字，发布时间，url）
            yield scrapy.Request(url=url,callback=self.parseSecond)
    def parseSecond(self,response):
        div_list=response.xpath('//div[@class="data_row news_article clearfix"]')
        # print(len(div_list))
        for div in div_list:
            head=div.xpath('.//div[@class="news_title"]/h3/a/text()').extract_first()
            url=div.xpath('.//div[@class="news_title"]/h3/a/@href').extract_first()
            imgUrl=div.xpath('./a/img/@src').extract_first()
            publish_t=div.xpath('.//div[@class="news_tag"]/span/text()').extract_first()
            tag=div.xpath('.//div[@class="keywords"]/a/text()').extract()
            tag="".join(tag)

middlewares.py

from scrapy import signals

class WangyiproDownloaderMiddleware(object):

    def process_request(self, request, spider):

        return None
    #拦截响应的对象(拦截下载器传递给Spider的响应对象)
    #request:响应对象对应的请求对象
    #response:拦截到的响应对象
    #spider:爬虫文件中对应的爬虫类的实例
    def process_response(self, request, response, spider):
        print(request.url+"这是下载中间件")

        return response

开启UA和robot以及下载中间件

settings.py

USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36'

# Obey robots.txt rules
ROBOTSTXT_OBEY = False

DOWNLOADER_MIDDLEWARES = {
   'wangyiPro.middlewares.WangyiproDownloaderMiddleware': 543,
}

 (6)网易爬虫程序wangyi.py

# -*- coding: utf-8 -*-
import scrapy
from selenium import webdriver  #第一步,导包

#第二步,实例化浏览器,保证浏览器只能实例化一次

class WangyiSpider(scrapy.Spider):
    name = 'wangyi'
    # allowed_domains = ['www.xxx.com']
    start_urls = ['https://news.163.com/']

    def __init__(self):
        # 第二步,实例化一个浏览器对象(保证实例化一次)
        self.bro=webdriver.Chrome(executable_path='./wangyiPro/chromedriver.exe')
        # urls = []
    def closed(self,spider):
        # 最后一步:必须在整个爬虫结束后,才关闭浏览器
        print('爬虫结束')
        self.bro.quit()

    def parse(self, response):
        lis=response.xpath('//div[@class="ns_area list"]/ul/li')
        indexs=[3,4,6,7,]
        li_list=[] #存储的就是国内,国际,军事,航空,无人机五个模块对应的li标签对象
        # global urls
        for index in indexs:
            li_list.append(lis[index])
        #获取四个板块中的链接和文字标题
        for li in li_list:
            url=li.xpath('./a/@href').extract_first()
            # urls.append(url)
            title=li.xpath('./a/text()').extract_first()
            # print(url+":"+title)
            print(url)
            #对每一个板块对应的url发起请求，获取页面数据（标题，缩略图，关键字，发布时间，url）
            yield scrapy.Request(url=url,callback=self.parseSecond)
    def parseSecond(self,response):
        div_list=response.xpath('/html/body/div/div[3]/div[4]/div[1]/div/div/ul/li/div/div')
        print(len(div_list))
        for div in div_list:
            head=div.xpath('.//div[@class="news_title"]/h3/a/text()').extract_first()
            url=div.xpath('.//div[@class="news_title"]/h3/a/@href').extract_first()
            imgUrl=div.xpath('./a/img/@src').extract_first()
            publish_t=div.xpath('.//div[@class="news_tag"]/span/text()').extract_first()
            tag=div.xpath('.//div[@class="keywords"]/a/text()').extract()
            tag="".join(tag)

settings.py文件

DOWNLOADER_MIDDLEWARES = {
   'wangyiPro.middlewares.WangyiproDownloaderMiddleware': 543,
}
LOG_LEVEL = 'ERROR'

USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36'

# Obey robots.txt rules
ROBOTSTXT_OBEY = False

middlewares.py

from scrapy import signals
from time import sleep
from scrapy.http import HtmlResponse
class WangyiproDownloaderMiddleware(object):

    def process_request(self, request, spider):
        return None
    #拦截响应的对象(拦截下载器传递给Spider的响应对象)
    #request:响应对象对应的请求对象
    #response:拦截到的响应对象
    #spider:爬虫文件中对应的爬虫类的实例
    def process_response(self, request, response, spider):
        # print(request.url+"这是下载中间件")
        #响应对象中存储页面数据的篡改         #spider.url_list可以提前拿出来,问题出在这个http是否加s和无人机这个模块是独特的解析方式上边
        if request.url in['http://news.163.com/domestic/','http://news.163.com/world/','http://war.163.com/','http://news.163.com/air/']:
        # if request.url in spider.urls:
        #     print('this is process_response!!!!!!!!!!!!!!!!!!!!!!!!!1')
            spider.bro.get(url=request.url)
            sleep(2)
            #页面数据就是包含了动态加载出来的新闻数据对应的页面数据
            page_text=spider.bro.page_source

            return HtmlResponse(url=spider.bro.current_url,body=page_text,encoding='utf-8',request=request)
            # 实例化新的响应对象,作用域
        else:
            return response

(7)向下滑动与打印解析的内容(),这个有问题明天需要测试一下

 wangyi.py爬虫文件

# -*- coding: utf-8 -*-
import scrapy
from selenium import webdriver  #第一步,导包

#第二步,实例化浏览器,保证浏览器只能实例化一次

class WangyiSpider(scrapy.Spider):
    name = 'wangyi'
    # allowed_domains = ['www.xxx.com']
    start_urls = ['https://news.163.com/']

    def __init__(self):
        # 第二步,实例化一个浏览器对象(保证实例化一次)
        self.bro=webdriver.Chrome(executable_path='./wangyiPro/chromedriver.exe')
        # urls = []
    def closed(self,spider):
        # 最后一步:必须在整个爬虫结束后,才关闭浏览器
        print('爬虫结束')
        self.bro.quit()

    def parse(self, response):
        lis=response.xpath('//div[@class="ns_area list"]/ul/li')
        indexs=[3,4,6,7,]
        li_list=[] #存储的就是国内,国际,军事,航空,无人机五个模块对应的li标签对象
        # global urls
        for index in indexs:
            li_list.append(lis[index])
        #获取四个板块中的链接和文字标题
        for li in li_list:
            url=li.xpath('./a/@href').extract_first()
            # urls.append(url)
            title=li.xpath('./a/text()').extract_first()
            # print(url+":"+title)
            print(url)
            #对每一个板块对应的url发起请求，获取页面数据（标题，缩略图，关键字，发布时间，url）
            yield scrapy.Request(url=url,callback=self.parseSecond)
    def parseSecond(self,response):
        div_list=response.xpath('/html/body/div/div[3]/div[4]/div[1]/div/div/ul/li/div/div')
        print(len(div_list))
        for div in div_list:
            head=div.xpath('.//div[@class="news_title"]/h3/a/text()').extract_first()
            url=div.xpath('.//div[@class="news_title"]/h3/a/@href').extract_first()
            imgUrl=div.xpath('./a/img/@src').extract_first()
            publish_t=div.xpath('.//div[@class="news_tag"]/span/text()').extract_first()
            tag=div.xpath('.//div[@class="keywords"]/a/text()').extract()
            tags=[]
            for t in tag:
                t=t.strip('
 	')
                tags.append(t)
            tag="".join(tags)
            # print(head+":"+url+":"+imgUrl+":"+tag)

settings.py爬虫文件

# -*- coding: utf-8 -*-

# Scrapy settings for wangyiPro project
#
# For simplicity, this file contains only settings considered important or
# commonly used. You can find more settings consulting the documentation:
#
#     https://doc.scrapy.org/en/latest/topics/settings.html
#     https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
#     https://doc.scrapy.org/en/latest/topics/spider-middleware.html

BOT_NAME = 'wangyiPro'

SPIDER_MODULES = ['wangyiPro.spiders']
NEWSPIDER_MODULE = 'wangyiPro.spiders'


# Crawl responsibly by identifying yourself (and your website) on the user-agent
#USER_AGENT = 'wangyiPro (+http://www.yourdomain.com)'
USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36'

# 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://doc.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',
#}

# Enable or disable spider middlewares
# See https://doc.scrapy.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES = {
#    'wangyiPro.middlewares.WangyiproSpiderMiddleware': 543,
#}

# Enable or disable downloader middlewares
# See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
DOWNLOADER_MIDDLEWARES = {
   'wangyiPro.middlewares.WangyiproDownloaderMiddleware': 543,
}
LOG_LEVEL = 'ERROR'
# Enable or disable extensions
# See https://doc.scrapy.org/en/latest/topics/extensions.html
#EXTENSIONS = {
#    'scrapy.extensions.telnet.TelnetConsole': None,
#}

# Configure item pipelines
# See https://doc.scrapy.org/en/latest/topics/item-pipeline.html
#ITEM_PIPELINES = {
#    'wangyiPro.pipelines.WangyiproPipeline': 300,
#}

# Enable and configure the AutoThrottle extension (disabled by default)
# See https://doc.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://doc.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'

middlewares.py

# -*- coding: utf-8 -*-

# Define here the models for your spider middleware
#
# See documentation in:
# https://doc.scrapy.org/en/latest/topics/spider-middleware.html

from scrapy import signals
from time import sleep
from scrapy.http import HtmlResponse
class WangyiproDownloaderMiddleware(object):
    # 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.


    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
    #拦截响应的对象(拦截下载器传递给Spider的响应对象)
    #request:响应对象对应的请求对象
    #response:拦截到的响应对象
    #spider:爬虫文件中对应的爬虫类的实例
    def process_response(self, request, response, spider):
        # print(request.url+"这是下载中间件")
        #响应对象中存储页面数据的篡改         #spider.url_list可以提前拿出来
        if request.url in['http://news.163.com/domestic/','http://news.163.com/world/','http://war.163.com/','http://news.163.com/air/']:
        # if request.url in spider.urls:
        #     print('this is process_response!!!!!!!!!!!!!!!!!!!!!!!!!1')
            spider.bro.get(url=request.url)
            sleep(2)

            # js='window.scrollTo(0,documnet.body.scrollHeight)'
            # spider.bro.execute_script(js)
            # sleep(2)  #缓冲加载数据,一定要给予浏览器一定的缓冲加载数据的时间
            #页面数据就是包含了动态加载出来的新闻数据对应的页面数据

            page_text=spider.bro.page_source

            return HtmlResponse(url=spider.bro.current_url,body=page_text,encoding='utf-8',request=request)
            # 实例化新的响应对象,作用域
        else:
            return response

 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 WangyiproItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    pass

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


class WangyiproPipeline(object):
    def process_item(self, item, spider):
        # print(item['title']+':'+item['content'])
        return item

执行:

scrapy crawl wangyi --nolog

(8)加上传入管道和传递item,以及meta传递参数和获取文章内容的编写

爬虫文件wangyi.py

# -*- coding: utf-8 -*-
import scrapy
from selenium import webdriver  #第一步,导包
from wangyiPro.items import WangyiproItem
#第二步,实例化浏览器,保证浏览器只能实例化一次

class WangyiSpider(scrapy.Spider):
    name = 'wangyi'
    # allowed_domains = ['www.xxx.com']
    start_urls = ['https://news.163.com/']

    def __init__(self):
        # 第二步,实例化一个浏览器对象(保证实例化一次)
        self.bro=webdriver.Chrome(executable_path='./wangyiPro/chromedriver.exe')
        # urls = []
    def closed(self,spider):
        # 最后一步:必须在整个爬虫结束后,才关闭浏览器
        print('爬虫结束')
        self.bro.quit()

    def parse(self, response):
        lis=response.xpath('//div[@class="ns_area list"]/ul/li')
        indexs=[3,4,6,7,]
        li_list=[] #存储的就是国内,国际,军事,航空,无人机五个模块对应的li标签对象
        # global urls
        for index in indexs:
            li_list.append(lis[index])
        #获取四个板块中的链接和文字标题
        for li in li_list:
            url=li.xpath('./a/@href').extract_first()
            # urls.append(url)
            title=li.xpath('./a/text()').extract_first()
            # print(url+":"+title)
            print(url)
            #对每一个板块对应的url发起请求，获取页面数据（标题，缩略图，关键字，发布时间，url）
            yield scrapy.Request(url=url,callback=self.parseSecond,meta={'title':title})#请求传参
    def parseSecond(self,response):
        div_list=response.xpath('/html/body/div/div[3]/div[4]/div[1]/div/div/ul/li/div/div')
        print(len(div_list))
        for div in div_list:
            head=div.xpath('.//div[@class="news_title"]/h3/a/text()').extract_first()
            url=div.xpath('.//div[@class="news_title"]/h3/a/@href').extract_first()
            imgUrl=div.xpath('./a/img/@src').extract_first()
            publish_t=div.xpath('.//div[@class="news_tag"]/span/text()').extract_first()
            tag=div.xpath('.//div[@class="keywords"]/a/text()').extract()
            tags=[]
            for t in tag:
                t=t.strip('
 	')
                tags.append(t)
            tag="".join(tags)

            #获取meta传递过来的数据值title
            title=response.meta['title']
            #实例化item对象,将解析到的数据值存储到item对象中
            item =WangyiproItem()
            item['head']=head
            item['url']=url
            item['imgUrl']=imgUrl
            item['publish_t']=publish_t
            item['tag']=tag
            item['title']=title

            #对url发起请求,获取对应页面中存储的新闻内容数据
            yield scrapy.Request(url=url, callback=self.getContent, meta={'item': item})
            # print(head+":"+url+":"+imgUrl+":"+tag)
    def getContent(self,response):
        #获取传递过来的item
        item=response.meta['item']

        #解析当前页面中存储的新闻数据
        content_list=response.xpath('//div[@class="post_text"]/p/text()').extract()
        content="".join(content_list)
        item['content']=content
        yield item

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 WangyiproItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    # pass
    head = scrapy.Field()
    url = scrapy.Field()
    imgUrl = scrapy.Field()
    publish_t = scrapy.Field()
    tag = scrapy.Field()
    title = scrapy.Field()
    content = scrapy.Field()

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


class WangyiproPipeline(object):
    def process_item(self, item, spider):
        print(item['title']+':'+item['content'])
        return item

settings.py

# -*- coding: utf-8 -*-

# Scrapy settings for wangyiPro project
#
# For simplicity, this file contains only settings considered important or
# commonly used. You can find more settings consulting the documentation:
#
#     https://doc.scrapy.org/en/latest/topics/settings.html
#     https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
#     https://doc.scrapy.org/en/latest/topics/spider-middleware.html

BOT_NAME = 'wangyiPro'

SPIDER_MODULES = ['wangyiPro.spiders']
NEWSPIDER_MODULE = 'wangyiPro.spiders'


# Crawl responsibly by identifying yourself (and your website) on the user-agent
#USER_AGENT = 'wangyiPro (+http://www.yourdomain.com)'
USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36'

# 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://doc.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',
#}

# Enable or disable spider middlewares
# See https://doc.scrapy.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES = {
#    'wangyiPro.middlewares.WangyiproSpiderMiddleware': 543,
#}

# Enable or disable downloader middlewares
# See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
DOWNLOADER_MIDDLEWARES = {
   'wangyiPro.middlewares.WangyiproDownloaderMiddleware': 543,
}
LOG_LEVEL = 'ERROR'
# Enable or disable extensions
# See https://doc.scrapy.org/en/latest/topics/extensions.html
#EXTENSIONS = {
#    'scrapy.extensions.telnet.TelnetConsole': None,
#}

# Configure item pipelines
# See https://doc.scrapy.org/en/latest/topics/item-pipeline.html
ITEM_PIPELINES = {
   'wangyiPro.pipelines.WangyiproPipeline': 300,
}

# Enable and configure the AutoThrottle extension (disabled by default)
# See https://doc.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://doc.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'

middlewares.py

# -*- coding: utf-8 -*-

# Define here the models for your spider middleware
#
# See documentation in:
# https://doc.scrapy.org/en/latest/topics/spider-middleware.html

from scrapy import signals
from time import sleep
from scrapy.http import HtmlResponse
class WangyiproDownloaderMiddleware(object):
    # 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.


    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
    #拦截响应的对象(拦截下载器传递给Spider的响应对象)
    #request:响应对象对应的请求对象
    #response:拦截到的响应对象
    #spider:爬虫文件中对应的爬虫类的实例
    def process_response(self, request, response, spider):
        # print(request.url+"这是下载中间件")
        #响应对象中存储页面数据的篡改         #spider.url_list可以提前拿出来
        if request.url in['http://news.163.com/domestic/','http://news.163.com/world/','http://war.163.com/','http://news.163.com/air/']:
        # if request.url in spider.urls:
        #     print('this is process_response!!!!!!!!!!!!!!!!!!!!!!!!!1')
            spider.bro.get(url=request.url)
            sleep(2)

            # js='window.scrollTo(0,documnet.body.scrollHeight)'
            # spider.bro.execute_script(js)
            # sleep(2)  #缓冲加载数据,一定要给予浏览器一定的缓冲加载数据的时间
            #页面数据就是包含了动态加载出来的新闻数据对应的页面数据

            page_text=spider.bro.page_source

            return HtmlResponse(url=spider.bro.current_url,body=page_text,encoding='utf-8',request=request)
            # 实例化新的响应对象,作用域
        else:
            return response

主要是五个文件的编写:

wangyi.py爬虫文件

middlewares.py

settings.py

items.py

pipelines.py

(9)