spalsh安装及简单使用

• selenium是浏览器测试自动化工具，很容易完成鼠标点击，翻页等动作，确定是一次只能加载一个页面，无法异步渲染页面，也就限制了selenium爬虫的抓取效率。

• splash可以实现异步渲染页面，可以同时渲染几个页面。缺点是在页面点击，，模拟登陆方面没有selenium灵活。

1. 安装 docker和splash

可以看我之前写的 如何安装并启动docker和splash

https://www.cnblogs.com/zichliang/p/15796638.html

注意：！！

#root用户开放8050端口

[root@wzy_woyun ~]# firewall-cmd --permanent --add-port=8050/tcp

success

[root@wzy_woyun ~]# firewall-cmd --reload

Success

普通的python 动态lua脚本

1. 添加请求头 请求url

function main(splash,args)
          local url=args.url
          splash:set_user_agent("Mozilla/5.0Chrome/69.0.3497.100Safari/537.36")
          splash:go(url)
          splash:wait(2)
          splash:go(url)
          return{
          html=splash:html(),
          png = splash:png()
          }
end

1. 通过滑动 来完成动态加载

function main(splash, args)
      splash:go(args.url)
      local scroll_to = splash:jsfunc("window.scrollTo")
      scroll_to(0, 2800)
      splash:set_viewport_full()
      splash:wait(5)
      return {html=splash:html()}
end

结合scarpy 来使用首先需要在settings中添加

SPLASH_URL = 'http://192.168.2.55:8050/'

DOWNLOADER_MIDDLEWARES = {
    'curreny.middlewares.ProcessAllException': 200,
    'curreny.middlewares.CurrenyDownloaderMiddleware': 543,
    'scrapy_splash.SplashCookiesMiddleware': 723,
    'scrapy_splash.SplashMiddleware': 725,
    'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware': 810,
}

DUPEFILTER_CLASS = 'scrapy_splash.SplashAwareDupeFilter'

# 缓存
HTTPCACHE_STORAGE = 'scrapy_splash.SplashAwareFSCacheStorage'

然后 在spider中添加lua脚本

"""

平潭综合实验区人民政府

"""
import copy
import re
import time

import scrapy
import scrapy_splash
from curreny.items import CurrenyItem

class PingtancomprehensiveexperimentgovproSpider(scrapy.Spider):
    name = 'PingTanComprehensiveExperimentGovPro'
    # allowed_domains = ['xxx.com']
    start_urls = ['http://www.pingtan.gov.cn/jhtml/cn/8423']

    def start_requests(self):
        lua="""
            function main(splash, args)
              splash.images_enabled = false
              assert(splash:go(args.url))
              assert(splash:wait(1))
              js = string.format("document.querySelector('body > div.container > div.main.clearfix > div > div.page > span:nth-child(4) > a').click();", args.page)
              splash:runjs(js)
              assert(splash:wait(5))
              return splash:html()
            end
        """
        url="http://www.pingtan.gov.cn/jhtml/cn/8423"
        for page in range(1,105):
            yield scrapy_splash.SplashRequest(
                url=url,
                endpoint="execute",
                args={
                    "url":url,
                    "lua_source":lua,
                    "page":page,
                    "wait":1
                },
                callback=self.parse
            )

    def parse(self, response,**kwargs):
        item = CurrenyItem()

        for li in response.css("body > div.container > div.main.clearfix > div > div.info_list.list > ul > li"):
            item["title_url"] = 'http://www.pingtan.gov.cn' + str(li.css("a::attr(href)").get())
            item["title_name"] = li.css("a::attr(title)").get()
            item["title_date"] = li.css("span::text").get()

            yield scrapy.Request(
                url=item['title_url'],
                callback=self.parse_detail,
                meta={'item': copy.deepcopy(item)}
            )

    # 详情页解析
    def parse_detail(self, response):
        item = response.meta['item']
        item['content_html'] = response.css('.detail').get()
        print(item['title_name'], item['title_url'], item['title_date'], )
        yield item