转：https://zhuanlan.zhihu.com/p/26701898

1.自定爬虫方法

# -*- coding: utf-8 -*-
import scrapy
import requests
from proxy.items import ProxyItem
class DxdlspiderSpider(scrapy.Spider):
    name = 'dxdlspider'
    allowed_domains = ['xicidaili.com']
    start_urls = ['http://www.xicidaili.com/wt/']

    def parse(self, response):
        items=[]
        #获取网页信息
        add_list1=response.xpath('//tr[@class=""]');
        add_list2=response.xpath('//tr[@class="odd"]');
        add_list=add_list1+add_list2;
        print (add_list)
        test=testProxy();
        for add in add_list:
            item=ProxyItem();
            #print(add.xpath('./td//text()')[0].extract()+':'+add.xpath('./td//text()')[1].extract())
            address=add.xpath('./td//text()')[0].extract() + ':' + add.xpath('./td//text()')[1].extract()

            #测试是否能用
            # if test.ipUtils(address):
            #     item['address']=address
            #     items.append(item)

            item['address'] = address
            items.append(item)

        return items



class testProxy:

    def ipUtils(self,proxy):
        # 设置代理头
        proxies = {'http': proxy}
        print('正在测试：{}'.format(proxies))
        try:
            r = requests.get('http://www.baidu.com', proxies=proxies, timeout=3)
            if r.status_code == 200:
                print('该代理：{}成功存活'.format(proxy))
                return True
        except:
            print('该代理{}失效！'.format(proxies))
            return False

2、items.py

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

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

import scrapy


class ProxyItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    address=scrapy.Field();

3.pipelins.py存入数据库

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

# Define your item pipelines here
#
# Don't forget to add your pipeline to the ITEM_PIPELINES setting
# See: https://doc.scrapy.org/en/latest/topics/item-pipeline.html

import os
import requests
import json
import codecs
import pymysql

class ProxyPipeline(object):
    def process_item(self, item, spider):
        return item




#将数据存入数据库
class Rmysql(object):
    def process_item(self, item, spider):

        #抓取数据存入mysql

        #将数据从item中拿出来
        address=item['address'];


        #和本地的数据库连接起来
        connection=pymysql.connect(
            host='localhost',  # 连接的是本地数据库
            user='root',        # 自己的mysql用户名
            passwd='123456',  # 自己的密码
            db='scrapyDB',      # 数据库的名字
            charset='utf8mb4',     # 默认的编码方式：
            cursorclass=pymysql.cursors.DictCursor)

        #插库
        try:
            with connection.cursor() as cursor:
                #创建更新数据库的sql
                sql="""INSERT INTO address(address) 
                    VALUES (%s)"""

                #执行sql
                cursor.execute(sql,(address))
            #提交插入数据
            connection.commit()
        finally:
            #关闭资源   的第二个参数可以将sql缺省语句补全，一般以元组的格式
            connection.close()
        return item

4.settings.py这里要说一下，我是根据知乎一大哥学的python爬虫点击打开链接，一年前这个网站还没有反爬虫他直接获取txt文件，但是我写的时候，发现报了503，很尴尬。所以试着自己写的，最后成功了，这里在settings.py中，模拟user-agent信息

# -*- coding: utf-8 -*-
import random
# user agent 列表
USER_AGENT_LIST = [
    'MSIE (MSIE 6.0; X11; Linux; i686) Opera 7.23',
    'Opera/9.20 (Macintosh; Intel Mac OS X; U; en)',
    'Opera/9.0 (Macintosh; PPC Mac OS X; U; en)',
    'iTunes/9.0.3 (Macintosh; U; Intel Mac OS X 10_6_2; en-ca)',
    'Mozilla/4.76 [en_jp] (X11; U; SunOS 5.8 sun4u)',
    'iTunes/4.2 (Macintosh; U; PPC Mac OS X 10.2)',
    'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:5.0) Gecko/20100101 Firefox/5.0',
    'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:9.0) Gecko/20100101 Firefox/9.0',
    'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:16.0) Gecko/20120813 Firefox/16.0',
    'Mozilla/4.77 [en] (X11; I; IRIX;64 6.5 IP30)',
    'Mozilla/4.8 [en] (X11; U; SunOS; 5.7 sun4u)'
]
# Scrapy settings for proxy project
#
# For simplicity, this file contains only settings considered important or
# commonly used. You can find more settings consulting the documentation:
#
#     https://doc.scrapy.org/en/latest/topics/settings.html
#     https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
#     https://doc.scrapy.org/en/latest/topics/spider-middleware.html

BOT_NAME = 'proxy'

SPIDER_MODULES = ['proxy.spiders']
NEWSPIDER_MODULE = 'proxy.spiders'
DOWNLOAD_DELAY = 1
# 随机生成user agent
USER_AGENT = random.choice(USER_AGENT_LIST)

ITEM_PIPELINES ={'proxy.pipelines.Rmysql': 500}

# Crawl responsibly by identifying yourself (and your website) on the user-agent
#USER_AGENT = 'proxy (+http://www.yourdomain.com)'

# Obey robots.txt rules
ROBOTSTXT_OBEY = True

# Configure maximum concurrent requests performed by Scrapy (default: 16)
#CONCURRENT_REQUESTS = 32

# Configure a delay for requests for the same website (default: 0)
# See https://doc.scrapy.org/en/latest/topics/settings.html#download-delay
# See also autothrottle settings and docs
#DOWNLOAD_DELAY = 3
# The download delay setting will honor only one of:
#CONCURRENT_REQUESTS_PER_DOMAIN = 16
#CONCURRENT_REQUESTS_PER_IP = 16

# Disable cookies (enabled by default)
#COOKIES_ENABLED = False

# Disable Telnet Console (enabled by default)
#TELNETCONSOLE_ENABLED = False

# Override the default request headers:
#DEFAULT_REQUEST_HEADERS = {
#   'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
#   'Accept-Language': 'en',
#}

# Enable or disable spider middlewares
# See https://doc.scrapy.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES = {
#    'proxy.middlewares.ProxySpiderMiddleware': 543,
#}

# Enable or disable downloader middlewares
# See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
#DOWNLOADER_MIDDLEWARES = {
#    'proxy.middlewares.ProxyDownloaderMiddleware': 543,
#}

# Enable or disable extensions
# See https://doc.scrapy.org/en/latest/topics/extensions.html
#EXTENSIONS = {
#    'scrapy.extensions.telnet.TelnetConsole': None,
#}

# Configure item pipelines
# See https://doc.scrapy.org/en/latest/topics/item-pipeline.html
#ITEM_PIPELINES = {
#    'proxy.pipelines.ProxyPipeline': 300,
#}

# Enable and configure the AutoThrottle extension (disabled by default)
# See https://doc.scrapy.org/en/latest/topics/autothrottle.html
#AUTOTHROTTLE_ENABLED = True
# The initial download delay
#AUTOTHROTTLE_START_DELAY = 5
# The maximum download delay to be set in case of high latencies
#AUTOTHROTTLE_MAX_DELAY = 60
# The average number of requests Scrapy should be sending in parallel to
# each remote server
#AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0
# Enable showing throttling stats for every response received:
#AUTOTHROTTLE_DEBUG = False

# Enable and configure HTTP caching (disabled by default)
# See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings
#HTTPCACHE_ENABLED = True
#HTTPCACHE_EXPIRATION_SECS = 0
#HTTPCACHE_DIR = 'httpcache'
#HTTPCACHE_IGNORE_HTTP_CODES = []
#HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage'