python使用Scrapy项目添加代理中间件的步骤和代码实现

在项目中新建middlewares.py文件(./项目名/middlewares.py)     

import base64            
import sys
import random

PY3 = sys.version_info[0] >= 3

def base64ify(bytes_or_str):
            if PY3 and isinstance(bytes_or_str, str):
                input_bytes = bytes_or_str.encode('utf8')
            else:
                input_bytes = bytes_or_str

            output_bytes = base64.urlsafe_b64encode(input_bytes)
            if PY3:
                return output_bytes.decode('ascii')
            else:
                return output_bytes

class ProxyMiddleware(object):                
            def process_request(self, request, spider):
                # 代理服务器
                proxyHost = "ip.hahado.cn"
                proxyPort = "31111"

                # 代理验证信息
                proxyUser = "username"
                proxyPass = "password"

                # [版本>=2.6.2](https://docs.scrapy.org/en/latest/news.html?highlight=2.6.2#scrapy-2-6-2-2022-07-25)无需添加验证头,会自动在请求头中设置Proxy-Authorization     
                request.meta['proxy'] = "http://{0}:{1}@{2}:{3}".format(proxyUser,proxyPass，proxyHost，proxyPort)

                # 版本<2.6.2 需要手动添加代理验证头
                # request.meta['proxy'] = "http://{0}:{1}".format(proxyHost,proxyPort)
                # request.headers['Proxy-Authorization'] = 'Basic ' +  base64ify(proxyUser + ":" + proxyPass)                    

                # 设置IP切换头(根据需求)
                # tunnel = random.randint(1,10000)
                # request.headers['Proxy-Tunnel'] = str(tunnel)

                # 每次访问后关闭TCP链接，强制每次访问切换IP
                request.header['Connection'] = "Close"

修改项目配置文件 (./项目名/settings.py)

    DOWNLOADER_MIDDLEWARES = {
        '项目名.middlewares.ProxyMiddleware': 100,
    }