python 爬虫 应对 网页反爬虫的 设置

凡是使用爬虫去爬取数据时，都应提前想想爬取的网站上有没有反爬虫，你写的代码都应该有代理吧？

解决方案：在settings文件中添加

USER_AGENT = 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36'

附录：常见的user_agent：

   

USER_AGENTS = [
        "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; AcooBrowser; .NET CLR 1.1.4322; .NET CLR 2.0.50727)",
        "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; Acoo Browser; SLCC1; .NET CLR 2.0.50727; Media Center PC 5.0; .NET CLR 3.0.04506)",
        "Mozilla/4.0 (compatible; MSIE 7.0; AOL 9.5; AOLBuild 4337.35; Windows NT 5.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)",
        "Mozilla/5.0 (Windows; U; MSIE 9.0; Windows NT 9.0; en-US)",
        "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Win64; x64; Trident/5.0; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET CLR 2.0.50727; Media Center PC 6.0)",
        "Mozilla/5.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET CLR 1.0.3705; .NET CLR 1.1.4322)",
        "Mozilla/4.0 (compatible; MSIE 7.0b; Windows NT 5.2; .NET CLR 1.1.4322; .NET CLR 2.0.50727; InfoPath.2; .NET CLR 3.0.04506.30)",
        "Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN) AppleWebKit/523.15 (KHTML, like Gecko, Safari/419.3) Arora/0.3 (Change: 287 c9dfb30)",
        "Mozilla/5.0 (X11; U; Linux; en-US) AppleWebKit/527+ (KHTML, like Gecko, Safari/419.3) Arora/0.6",
        "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.2pre) Gecko/20070215 K-Ninja/2.1.1",
        "Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9) Gecko/20080705 Firefox/3.0 Kapiko/3.0",
        "Mozilla/5.0 (X11; Linux i686; U;) Gecko/20070322 Kazehakase/0.4.5",
        "Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.8) Gecko Fedora/1.9.0.8-1.fc10 Kazehakase/0.5.6",
        "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.56 Safari/535.11",
        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_3) AppleWebKit/535.20 (KHTML, like Gecko) Chrome/19.0.1036.7 Safari/535.20",
        "Opera/9.80 (Macintosh; Intel Mac OS X 10.6.8; U; fr) Presto/2.9.168 Version/11.52",
    ]

如果还不能解决的话，还需要设置以下的

1.添加IP代理：

  

  PROXIES = [
        {'ip_port': '111.11.228.75:80', 'user_pass': ''},
        {'ip_port': '120.198.243.22:80', 'user_pass': ''},
        {'ip_port': '111.8.60.9:8123', 'user_pass': ''},
        {'ip_port': '101.71.27.120:80', 'user_pass': ''},
        {'ip_port': '122.96.59.104:80', 'user_pass': ''},
        {'ip_port': '122.224.249.122:8088', 'user_pass': ''},
    ]

2.改机器人协议以及cookie

ROBOTSTXT_OBEY = False

COOKIES_ENABLED = False

3.设置延迟   

DOWNLOAD_DELAY = 3

四.在分段函数中所要爬取的url有反爬虫，例如下图加了显示状态码分辨出来的

       

 def start_requests(self):
            bash_url = 'http://shoudian.bjx.com.cn/NewsList?id=85'
            last_url = '&page='
            for i in range(1,10):#10
                if i == 1:
                    url = bash_url
                else:
                    url = bash_url + last_url + str(i)
                print(url)
                print(requests.get(url).status_code)
                if requests.get(url).status_code != 403:
                    yield Request(url, self.parse)
                    print(url)
                else:
                    break

解决方案：在请求的url后面添加头文件如以下，头文件可以从问题三的附录中随机取

      

  def start_requests(self):
            bash_url = 'http://shoudian.bjx.com.cn/NewsList?id=85'
            last_url = '&page='
            for i in range(1,10):#10
                if i == 1:
                    url = bash_url
                else:
                    url = bash_url + last_url + str(i)
                url_code = requests.get(url,headers={'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36'}).status_code
                if url_code != 403:
                    yield Request(url, self.parse,headers={'User-Agent':'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36'})
                else:
                    break

 
原文链接：https://blog.csdn.net/weixin_41931602/article/details/80200695