代理操作

下载中间件作用： 拦截请求，可以将请求的ip进行更换

流程：

 　　1.下载中间件类的自制定

　　　　a) object

　　　　b) 重写process_request(self, request, spider)的方法

　　2.配置文件中进行下载中间价的开启

　　middlewares.py

# -*- coding: utf-8 -*-

# Define here the models for your spider middleware
#
# See documentation in:
# https://doc.scrapy.org/en/latest/topics/spider-middleware.html

from scrapy import signals


class middleadd(object):

    def process_request(self, request, spider):
        request.meta["proxy"] = "157.65.31.220:3128"

settings.py里开启中间件

spider/midtest.py

import scrapy


class MidtestSpider(scrapy.Spider):
    name = 'midtest'
    # allowed_domains = ['www.baidu.com']
    start_urls = ["https://www.baidu.com/s?wd=ip"]

    def parse(self, response):
        fp = open("record.html", "w",encoding="utf-8")
        fp.write(response.text)

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