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Scrapy框架结合Spynner采集需进行js,ajax动态加

Scrapy框架结合Spynner采集需进行js,ajax动态加

作者: comboo | 来源:发表于2016-09-07 22:19 被阅读400次

    对于网页的采集有这样几种:
    1.静态网页
    2.动态网页(需进行js,ajax动态加载数据的网页)
    3.需进行模拟登录后才能采集的网页
    4.加密的网页

    3,4的解决方案和思路会在后续blog中陈述
    现在只针对1,2的解决方案与思路:
    一.静态网页
    对于静态网页的采集解析方法很多很多!java,python都提供了很多的工具包或框架,例如java的httpclient,Htmlunit,Jsoup,HtmlParser等,Python的urllib,urllib2,BeautifulSoup,Scrapy等,不详述,网上资料很多的。

    二.动态网页
    对于采集来说的动态网页是那些需要经过js,ajax动态加载来获取数据的网页,采集数据的方案分为两种:
    1.通过抓包工具分析js,ajax的请求,模拟该请求获取js加载后的数据。
    2.调用浏览器的内核,获取加载后的网页源码,然后对源码经行解析
    一个研究爬虫的人js是必须要会得东西,网上学习资料很多,不陈述,写该条只为文章的完整性
    调用浏览器内核的工具包Java也有几个,但是不是今天所讲的重点,今天的重点是文章的标题Scrapy框架结合Spynner采集需进行js,ajax动态加载的网页并提取网页信息(以采集微信公众号文章列表为例)

    Start......
    1.创建个微信公众号文章列表采集项目(以下简称微采集)

    命令代码 收藏代码

    scrapy startproject weixin

    2.在spider目录下创建一个采集spider文件

    Python代码 收藏代码

    vim weixinlist.py

    写入如下代码
    
    Python代码 收藏代码

    from weixin.items import WeixinItem
    import sys
    sys.path.insert(0,'..')
    import scrapy
    import time
    from scrapy import Spider

    class MySpider(Spider):
    name = 'weixinlist'
    allowed_domains = []
    start_urls = [
    'http://weixin.sogou.com/gzh?openid=oIWsFt5QBSP8mn4Jx2WSGw_rCNzQ',
    ]
    download_delay = 1
    print('start init....')

        def parse(self, response):  
                sel=scrapy.Selector(response)  
                print('hello,world!')  
                print(response)  
                print(sel)  
                list=sel.xpath('//div[@class="txt-box"]/h4')  
                items=[]  
                for single in list:  
                        data=WeixinItem()  
                        title=single.xpath('a/text()').extract()  
                        link=single.xpath('a/@href').extract()  
                        data['title']=title  
                        data['link']=link  
                        if len(title)>0:  
                                print(title[0].encode('utf-8'))  
                                print(link)  
    

    3.在items.py中加入WeixinItem类

    Python代码 收藏代码

    import scrapy

    class WeixinItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    title=scrapy.Field()
    link=scrapy.Field()

    4.在items.py的同级目录下创建一个下载中间件downloadwebkit.py,并向其中写入如下代码:

    Python代码 收藏代码

    import spynner
    import pyquery
    import time
    import BeautifulSoup
    import sys
    from scrapy.http import HtmlResponse
    class WebkitDownloaderTest( object ):
    def process_request( self, request, spider ):

    if spider.name in settings.WEBKIT_DOWNLOADER:

    if( type(request) is not FormRequest ):

                browser = spynner.Browser()  
                browser.create_webview()  
                browser.set_html_parser(pyquery.PyQuery)  
                browser.load(request.url, 20)  
                try:  
                        browser.wait_load(10)  
                except:  
                        pass  
                string = browser.html  
                string=string.encode('utf-8')  
                renderedBody = str(string)  
                return HtmlResponse( request.url, body=renderedBody )  
    

    这段代码就是调用浏览器内核,获取网页加载后的源码
    5.在setting.py文件中进行配置,声明下载使用下载中间件
    在底部加上如下代码:

    Python代码 收藏代码

    which spider should use WEBKIT

    WEBKIT_DOWNLOADER=['weixinlist']

    DOWNLOADER_MIDDLEWARES = {
    'weixin.downloadwebkit.WebkitDownloaderTest': 543,
    }

    import os
    os.environ["DISPLAY"] = ":0"

    6.运行程序:
    运行命令:****

    Python代码 收藏代码

    scrapy crawl weixinlist

    运行结果: 
    
    Python代码 收藏代码

    kevinflynndeMacBook-Pro:spiders kevinflynn$ scrapy crawl weixinlist
    start init....
    2015-07-28 21:13:55 [scrapy] INFO: Scrapy 1.0.1 started (bot: weixin)
    2015-07-28 21:13:55 [scrapy] INFO: Optional features available: ssl, http11
    2015-07-28 21:13:55 [scrapy] INFO: Overridden settings: {'NEWSPIDER_MODULE': 'weixin.spiders', 'SPIDER_MODULES': ['weixin.spiders'], 'BOT_NAME': 'weixin'}
    2015-07-28 21:13:55 [py.warnings] WARNING: :0: UserWarning: You do not have a working installation of the service_identity module: 'No module named service_identity'. Please install it from https://pypi.python.org/pypi/service_identity and make sure all of its dependencies are satisfied. Without the service_identity module and a recent enough pyOpenSSL to support it, Twisted can perform only rudimentary TLS client hostname verification. Many valid certificate/hostname mappings may be rejected.

    2015-07-28 21:13:55 [scrapy] INFO: Enabled extensions: CloseSpider, TelnetConsole, LogStats, CoreStats, SpiderState
    2015-07-28 21:13:55 [scrapy] INFO: Enabled downloader middlewares: HttpAuthMiddleware, DownloadTimeoutMiddleware, UserAgentMiddleware, RetryMiddleware, WebkitDownloaderTest, DefaultHeadersMiddleware, MetaRefreshMiddleware, HttpCompressionMiddleware, RedirectMiddleware, CookiesMiddleware, ChunkedTransferMiddleware, DownloaderStats
    2015-07-28 21:13:55 [scrapy] INFO: Enabled spider middlewares: HttpErrorMiddleware, OffsiteMiddleware, RefererMiddleware, UrlLengthMiddleware, DepthMiddleware
    2015-07-28 21:13:55 [scrapy] INFO: Enabled item pipelines:
    2015-07-28 21:13:55 [scrapy] INFO: Spider opened
    2015-07-28 21:13:55 [scrapy] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
    2015-07-28 21:13:55 [scrapy] DEBUG: Telnet console listening on 127.0.0.1:6023
    QFont::setPixelSize: Pixel size <= 0 (0)
    2015-07-28 21:14:08 [scrapy] DEBUG: Crawled (200) <GET http://weixin.sogou.com/gzh?openid=oIWsFt5QBSP8mn4Jx2WSGw_rCNzQ> (referer: None)
    hello,world!
    <200 http://weixin.sogou.com/gzh?openid=oIWsFt5QBSP8mn4Jx2WSGw_rCNzQ>
    <Selector xpath=None data=u'<html><head><meta http-equiv="X-UA-Compa'>
    互联网协议入门
    [u'http://mp.weixin.qq.com/s?__biz=MzA4MjEyNTA5Mw==&mid=210032701&idx=1&sn=6b1fc2bc5d4eb0f87513751e4ccf610c&3rd=MzA3MDU4NTYzMw==&scene=6#rd']
    自己动手写贝叶斯分类器给图书分类
    [u'http://mp.weixin.qq.com/s?__biz=MzA4MjEyNTA5Mw==&mid=210013947&idx=1&sn=1f36ba5794e22d0fb94a9900230e74ca&3rd=MzA3MDU4NTYzMw==&scene=6#rd']
    不当免费技术支持的10种方法
    [u'http://mp.weixin.qq.com/s?__biz=MzA4MjEyNTA5Mw==&mid=209998175&idx=1&sn=216106034a3b4afea6e67f813ce1971f&3rd=MzA3MDU4NTYzMw==&scene=6#rd']
    以 Python 为实例,介绍贝叶斯理论
    [u'http://mp.weixin.qq.com/s?__biz=MzA4MjEyNTA5Mw==&mid=209998175&idx=2&sn=2f3dee873d7350dfe9546ab4a9323c05&3rd=MzA3MDU4NTYzMw==&scene=6#rd']
    我从腾讯那“偷了”3000万QQ用户数据,出了份很有趣的...
    [u'http://mp.weixin.qq.com/s?__biz=MzA4MjEyNTA5Mw==&mid=209980651&idx=1&sn=11fd40a2dee5132b0de8d4c79a97dac2&3rd=MzA3MDU4NTYzMw==&scene=6#rd']
    如何用 Spark 快速开发应用?
    [u'http://mp.weixin.qq.com/s?__biz=MzA4MjEyNTA5Mw==&mid=209820653&idx=2&sn=23712b78d82fb412e960c6aa1e361dd3&3rd=MzA3MDU4NTYzMw==&scene=6#rd']
    一起来写个简单的解释器(1)
    [u'http://mp.weixin.qq.com/s?__biz=MzA4MjEyNTA5Mw==&mid=209797651&idx=1&sn=15073e27080e6b637c8d24b6bb815417&3rd=MzA3MDU4NTYzMw==&scene=6#rd']
    那个直接在机器码中改 Bug 的家伙
    [u'http://mp.weixin.qq.com/s?__biz=MzA4MjEyNTA5Mw==&mid=209762756&idx=1&sn=04ae1bc3a366d358f474ac3e9a85fb60&3rd=MzA3MDU4NTYzMw==&scene=6#rd']
    把一个库开源,你该做些什么
    [u'http://mp.weixin.qq.com/s?__biz=MzA4MjEyNTA5Mw==&mid=209762756&idx=2&sn=0ac961ffd82ead6078a60f25fed3c2c4&3rd=MzA3MDU4NTYzMw==&scene=6#rd']
    程序员的困境
    [u'http://mp.weixin.qq.com/s?__biz=MzA4MjEyNTA5Mw==&mid=209696436&idx=1&sn=8cb55b03c8b95586ba4498c64fa54513&3rd=MzA3MDU4NTYzMw==&scene=6#rd']
    2015-07-28 21:14:08 [scrapy] INFO: Closing spider (finished)
    2015-07-28 21:14:08 [scrapy] INFO: Dumping Scrapy stats:
    {'downloader/response_bytes': 131181,
    'downloader/response_count': 1,
    'downloader/response_status_count/200': 1,
    'finish_reason': 'finished',
    'finish_time': datetime.datetime(2015, 7, 28, 13, 14, 8, 958071),
    'log_count/DEBUG': 2,
    'log_count/INFO': 7,
    'log_count/WARNING': 1,
    'response_received_count': 1,
    'scheduler/dequeued': 1,
    'scheduler/dequeued/memory': 1,
    'scheduler/enqueued': 1,
    'scheduler/enqueued/memory': 1,
    'start_time': datetime.datetime(2015, 7, 28, 13, 13, 55, 688111)}
    2015-07-28 21:14:08 [scrapy] INFO: Spider closed (finished)
    QThread: Destroyed while thread is still running
    kevinflynndeMacBook-Pro:spiders kevinflynn$

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