python爬虫进阶篇：Scrapy中使用Selenium模拟Firefox火狐浏览器爬取网页信息

一、前言

接着上一篇的笔记，Scrapy爬取普通无反爬、静态页面的网页时可以顺利爬取我们要的信息。但是大部分情况下我们要的数据所在的网页它是动态加载出来的（ajax请求后传回前端页面渲染、js调用function等）。这种情况下需要使用selenium进行模拟人工操作浏览器行为，实现自动化采集动态网页数据。

二、环境搭建

• Scrapy框架的基本依赖包（前几篇有记录）
• selenium依赖包
  • pip install selenium==4.0.0a6.post2
  • pip install certifi
  • pip install urllib3==1.25.11
• 安装Firefox浏览器和对应版本的驱动包
  • 火狐浏览器我用的是最新版121.0
  • 驱动的版本为0.3.0，见上方资源链接
  • 把驱动放到python环境的Scripts文件夹下

三、代码实现

• settings设置

SPIDER_MIDDLEWARES = {
   'stock_spider.middlewares.StockSpiderSpiderMiddleware': 543,
}

DOWNLOADER_MIDDLEWARES = {
   'stock_spider.middlewares.StockSpiderDownloaderMiddleware': 543,
}

ITEM_PIPELINES = {
   'stock_spider.pipelines.StockSpiderPipeline': 300,
}

• middlewares中间件

from selenium.webdriver.firefox.options import Options as firefox_options


spider.driver = webdriver.Firefox(options=firefox_options())  # 指定使用的浏览器

• process_request

    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

        spider.driver.get("http://www.baidu.com")
        return None

• process_response

	from scrapy.http import HtmlResponse
    def process_response(self, request, response, spider):
        # Called with the response returned from the downloader.

        # Must either;
        # - return a Response object
        # - return a Request object
        # - or raise IgnoreRequest
        response_body = spider.driver.page_source

        return HtmlResponse(url=request.url, body=response_body, encoding='utf-8', request=request)

启动爬虫后就可以看到爬虫启动了浏览器驱动，接下来就可以实现各种模拟人工操作了