Scrapy-Splash使用及代理失败处理

PayneWu

发布于 2020-12-24 10:15:39

1.5K0

发布于 2020-12-24 10:15:39

文章被收录于专栏：积跬Coder

在日常做爬虫的时候肯定遇到这么一些问题，网页js渲染，接口加密等，以至于无法有效的获取数据，那么此时若想获取数据大致有两种方向，硬刚加密参数或使用渲染工具

二者的各有所不同？

刚加密参数：

优势：爬取速度快，实效性。损耗资源更少
劣势：耗费时间长，不懂的完全不会，会的也不一定能完全处理。难以在有效的时间内获取到数据

渲染工具：webdervi，puppeteer，pyppeteer，splash

优势：见效快、新手友好
劣势：爬取速度较慢、数据实效性难以保证、损耗资源多

那么相信做爬虫的小伙伴一定会有相对应的权衡

个人建议：如果可以刚参数，尽量刚参数。一方面是为了自己的在爬虫这条路上逐步前进，另一方面是更加符合当然如果实在搞不掉了，也可以使用渲染工具来进行模拟爬取

splash是什么？

Splash-一种JavaScript渲染服务

Splash是一种javascript渲染服务。这是一个带有HTTP API的轻量级Web浏览器，使用Twisted和QT5在Python 3中实现。（扭曲的）QT反应器用于使服务完全异步，从而允许通过QT主循环利用Webkit并发性。Splash的一些功能：

并行处理多个网页；
获取HTML结果和/或获取屏幕截图；
关闭图片或使用Adblock Plus规则来加快渲染速度；
在页面上下文中执行自定义JavaScript；
编写Lua浏览脚本;
在Splash-Jupyter Notebook中开发Splash Lua脚本。
以HAR格式获取详细的渲染信息。

话不多说，直接上splash。谁让我菜呢？

splash的安装

官方建议直接使用docker进行运行，docker安装

安装完成之后直接运行一下命令，使用docker运行splash

# 拉取splash
docker pull scrapinghub/splash
# 运行splash 
docker run -p 8050:8050 --name splash scrapinghub/splash
docker run -itd --name splash  -p 8050:8050 scrapinghub/splash --disable-lua-sandbox
# -p 向外暴露端口
# -d 守护进程方式运行(后台运行)
# --name 自定义昵称
# --disable-lua-sandbox 关闭沙盒模式。如果是在测试环境上可以直接去体验一下，功能更全。如果是在开发环境的话那就直接用正式的，虽然花里胡哨，但安全性并不好

此时你若无意外你可以访问'http://localhost:8050/'，就可以看到这样的画面

ok，到这里你就可以正常的使用它了，此时对于新手朋友的关照就已经结束了。接下来让我们对接scrapy。请确保scrapy可以正常运行。

# 创建项目
scrapy startproject <projectName>
# 创建spider
cd <projectName>
scrapy genspider httpbin httpbin.org/get

此时的项目结构应该如下

scrapy-splash用前配置

安装依赖

pip3 install scrapy-splash

settings.py

# 修改
SPIDER_MIDDLEWARES = {
    'scrapy_splash.SplashDeduplicateArgsMiddleware': 100,
}

DOWNLOADER_MIDDLEWARES = {
    'scrapy_splash.SplashCookiesMiddleware': 723,
    'scrapy_splash.SplashMiddleware': 725,
    'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware': 810,

}

# Configure scrapy-splash(加入)
SPLASH_URL = 'http://localhost:8050'
DUPEFILTER_CLASS = 'scrapy_splash.SplashAwareDupeFilter'
HTTPCACHE_STORAGE = 'scrapy_splash.SplashAwareFSCacheStorage'

Httbin.py

import scrapy
from scrapy_splash import SplashRequest

class HttbinSpider(scrapy.Spider):
    name = 'httpbin'
    # allowed_domains = ['httbin.org/get']
    start_urls = ['https://httpbin.org/get']

    def start_requests(self):
        print(self.start_urls[0])
        yield SplashRequest(
            url=self.start_urls[0],
            callback=self.parse
        )

    def parse(self, response, **kwargs):
        print(response)
        print(response.text)

# 运行爬虫
scrapy crawl httpbin

返回打印结果如下

2020-12-19 13:21:51 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://httpbin.org/get via http://localhost:8050/render.html> (referer: None)
<200 https://httpbin.org/get>
<html><head></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">{
  "args": {}, 
  "headers": {
    "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8", 
    "Accept-Encoding": "gzip, deflate", 
    "Accept-Language": "en", 
    "Host": "httpbin.org", 
    "User-Agent": "Scrapy/2.4.0 (+https://scrapy.org)", 
    "X-Amzn-Trace-Id": "Root=1-5fdd8dea-4ba769963b76178b56cd9724"
  }, 
  "origin": "220.202.249.12", 
  "url": "https://httpbin.org/get"
}
</pre></body></html>

---略

我们用浏览器访问一下"https://httpbin.org/get"

{
  "args": {}, 
  "headers": {
    "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9", 
    "Accept-Encoding": "gzip, deflate, br", 
    "Accept-Language": "zh-CN,zh;q=0.9,en;q=0.8,ja;q=0.7", 
    "Dnt": "1", 
    "Host": "httpbin.org", 
    "Sec-Fetch-Dest": "document", 
    "Sec-Fetch-Mode": "navigate", 
    "Sec-Fetch-Site": "none", 
    "Sec-Fetch-User": "?1", 
    "Upgrade-Insecure-Requests": "1", 
    "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 11_0_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36", 
    "X-Amzn-Trace-Id": "Root=1-5fdd8e50-48c6e9ec6dc7274967b9a493"
  }, 
  "origin": "220.202.249.12", 
  "url": "https://httpbin.org/get"
}

Ok，基本的使用也就到这里ok了。那么该如何配置代理呢？访问量一大,大多情况下都会封ip

设置代理

如下

import scrapy
from scrapy_splash import SplashRequest

class HttbinSpider(scrapy.Spider):
    name = 'httbin'
    # allowed_domains = ['httbin.org/get']
    start_urls = ['https://httpbin.org/get']

    def start_requests(self):
        print(self.start_urls[0])
        header = {
            'User-Agent': 'Mozilla/5.0 (Linux; U; Android 0.5; en-us) AppleWebKit/522  (KHTML, like Gecko) Safari/419.3'
        }
        # yield scrapy.Request(url=self.start_urls[0], callback=self.parse, headers=header)
        yield SplashRequest(
            url=self.start_urls[0],
            callback=self.parse,
            args={
                "wait": 3,
                "proxy": 'http://119.114.100.159:22992'
            }

        )

    def parse(self, response, **kwargs):
        print(response)
        print(response.text)

# 输出结果如下
2020-12-19 13:31:06 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://httpbin.org/get via http://localhost:8050/render.html> (referer: None)
<200 https://httpbin.org/get>
<html><head></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">{
  "args": {}, 
  "headers": {
    "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8", 
    "Accept-Encoding": "gzip, deflate", 
    "Accept-Language": "en", 
    "Host": "httpbin.org", 
    "User-Agent": "Scrapy/2.4.0 (+https://scrapy.org)", 
    "X-Amzn-Trace-Id": "Root=1-5fdd9017-7ef5ac1d6c66d99b52b200c0"
  }, 
  "origin": "119.114.100.159",     # 代理修改完成
  "url": "https://httpbin.org/get"
}
</pre></body></html>

使用中间件的方式设置代理

class MyHttpProxyMiddleware(object):
      def process_request(self, request, spider):
          request.meta['splash']['args']['proxy'] = proxyServer # （eg：'http://119.114.100.159:22992'）
        # 认证消息，没有可以不写
          # request.headers["Proxy-Authorization"] = proxyAuth

此时的中间件设置为

DOWNLOADER_MIDDLEWARES = {
    'learnSplash.middlewares.MyHttpProxyMiddleware': 724,
    'learnSplash.middlewares.MyUserAgentMiddleware': 400,
    'scrapy_splash.SplashCookiesMiddleware': 723,
    'scrapy_splash.SplashMiddleware': 725,
    'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware': 810,

}

对接代理错误点总结：

# settings中
SPLASH_URL = 'http://localhost:8050'
错写成SPLASH_URL = 'localhost:8050' (错误。验证方式command+鼠标左点击，若能正常显示splash页面即可)

# 爬虫文件中
args={
"wait": 3,
"proxy": 'http://119.114.100.159:22992'
}
# proxy，书写格式不对，缺少http等字段

# 中间键设置代理
# 错误点一：书写格式不对，缺少http等字段
# 权重设置错误
DOWNLOADER_MIDDLEWARES = {
   'learnSplash.middlewares.MyHttpProxyMiddleware': 724,
   'learnSplash.middlewares.MyUserAgentMiddleware': 400,
   'scrapy_splash.SplashCookiesMiddleware': 723,
   'scrapy_splash.SplashMiddleware': 725,
   'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware': 810,

}
# MyHttpProxyMiddleware的权重必须小于等于725，否则设定不成功。将使用原始ip访问