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  • scrapy入门二(分页抓取文章入库)

    分页抓取博客园新闻,先从列表里分析下一页按钮

    相关代码:

    # -*- coding: utf-8 -*-
    import scrapy
    
    from cnblogs.items import ArticleItem
    
    class BlogsSpider(scrapy.Spider):
        name = 'blogs'
        allowed_domains = ['news.cnblogs.com']
        start_urls = ['https://news.cnblogs.com/']
    
        def parse(self, response):
            articleList=response.css('.content')
    
            for item in articleList:
               # 由于详情页里浏览次数是js动态加载的,无法获取,这里需要传递过去
                viewcount = item.css('.view::text').extract_first()[:-3].strip()
                detailurl = item.css('.news_entry a::attr(href)').extract_first()
                detailurl = response.urljoin(detailurl)
                yield scrapy.Request(url=detailurl, callback=self.parse_detail, meta={"viewcount": viewcount})
            #获取下一页标签
            text=response.css('#sideleft > div.pager > a:last-child::text').extract_first().strip()
            if text=='Next >':
                next = response.css('#sideleft > div.pager > a:last-child::attr(href)').extract_first()
                url=response.urljoin(next)
    
                yield scrapy.Request(url=url,callback=self.parse)
    
        ##解析详情页内容
        def parse_detail(self, response):
            article=ArticleItem()
            article['linkurl']=response.url
            article['title']=response.css('#news_title a::text').extract_first()
            article['img'] = response.css('#news_content img::attr(src)').extract_first("default.png")
            article['source'] = response.css('.news_poster ::text').extract_first().strip()
            article['releasetime'] = response.css('.time::text').extract_first()[3:].strip()
            article['viewcount']= response.meta["viewcount"]
            article['content']=response.css('#news_body').extract_first("")
    
            yield article
    View Code

    写入数据库,先在setting.py页面配置mongo连接数据信息

    ROBOTSTXT_OBEY = True
    MONGODB_HOST='localhost'
    MONGO_PORT=27017
    MONGO_DBNAME='cnblogs'
    MONGO_DOCNAME='article'

    修改pipelines.py页面,相关代码

    # -*- 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
    import pymongo
    from scrapy.conf import settings
    from cnblogs.items import ArticleItem
    class CnblogsPipeline(object):
        #初始化信息
        def __init__(self):
    
            host = settings['MONGODB_HOST']
            port = settings['MONGO_PORT']
            db_name = settings['MONGO_DBNAME']
            client = pymongo.MongoClient(host=host, port=port)
            db = client[db_name]
            self.post=db[settings['MONGO_DOCNAME']]
            
         ##获取值进行入库   
        def process_item(self, item, spider):
            
            article=dict(item)
            self.post.insert(article)
    
            return item
    View Code
    __init__函数里,获取配置文件里的mongo连接信息,连接mongo库
    process_item函数里获取blogs.py里parse里yield返回的每一行,然后将数据入库

    最后需要在setting取消注释pipelines.py页面运行的注释,不修改(pipelines.py页面代码可能无法正常调用)
    ITEM_PIPELINES = {
       'cnblogs.pipelines.CnblogsPipeline': 300,
    }
    最后在Terminal终端运行命令:scrapy crawl blogs

    启用后便会开始进行抓取,结束后打开mongo客户端工具:库和表名创建的都是setting.py里配置的

     

    到此,3000条文章资讯数据一条不差的下载下来了

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  • 原文地址:https://www.cnblogs.com/dongml/p/8783738.html
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