源代码来自于基于Scrapy的Python3分布式淘宝爬虫，做了一些改动，对失效路径进行了更新，增加了一些内容。使用了随机User-Agent，scrapy-redis分布式爬虫，使用MySQL数据库存储数据。
目录
第一步 创建并配置scrapy项目
第二步 将数据导出至json文件和MySQL数据库
第三步 设置随机访问头User-Agent
第四步 配置scrapy-redis实现分布式爬虫
开发环境
电脑系统：macOS High Sierra
Python第三方库：scrapy、pymysql、scrapy-redis、redis、redis-py
Python版本：Anaconda 4.5.8 ,集成Python版本 3.6.4
数据库： MySQL 8.0.11、redis 4.0.1
第一步 创建scrapy项目
cmd输入：
scrapy startproject taobaocd taobao scrapy genspider -t basic tb taobao.com
1. 爬虫程序编写tb.py
在源代码的基础上添加了销量、产品描述信息的爬取；
更新了url分类判断的方式；
抓包取得的评论数网页格式有变化，更新了正则表达式。
# -*- coding: utf-8 -*-import scrapyimport refrom scrapy.http import Requestfrom taobao.items import TaobaoItemimport urllib.requestclass TbSpider(scrapy.Spider):
name = 'tb'
allowed_domains = ['taobao.com']
start_urls = ['http://taobao.com/'] def parse(self, response):
key = input("请输入你要爬取的关键词\t")
pages = input("请输入你要爬取的页数\t")
print("\n")
print("当前爬取的关键词是",key)
print("\n") for i in range(0, int(pages)):
url = "https://s.taobao.com/search?q=" + str(key) + "&s=" + str(44*i) yield Request(url=url, callback=self.page) pass
#搜索页
def page(self,response):
body = response.body.decode('utf-8', 'ignore')
pat_id = '"nid":"(.*?)"' #匹配id
pat_now_price = '"view_price":"(.*?)"' #匹配现价格
pat_address = '"item_loc":"(.*?)"' #匹配商家地址
pat_sale = '"view_sales":"(.*?)人付款"' #销量
all_id = re.compile(pat_id).findall(body)
all_now_price = re.compile(pat_now_price).findall(body)
all_address = re.compile(pat_address).findall(body)
all_sale = re.compile(pat_sale).findall(body) for i in range(0, len(all_id)):
this_id = all_id[i]
now_price = all_now_price[i]
address = all_address[i]
sale_count = all_sale[i]
url = "https://item.taobao.com/item.htm?id=" + str(this_id) yield Request(url=url, callback=self.next, meta={ 'now_price': now_price, 'address': address,'sale_count':sale_count}) pass
pass
#详情页
def next(self, response):
item = TaobaoItem()
url = response.url
#由于淘宝和天猫的某些信息采用不同方式的Ajax加载，做一个分类
if 'tmall' in url: #天猫、天猫超市、天猫国际
title = response.xpath("//html/head/title/text()").extract() #获取商品名称
#price = response.xpath("//span[@class='tm-count']/text()").extract()
#这里获取商品原价格-但一直抓到的是空值，Xpath在xpath finder里验证有效，暂时不知道为什么。。。由于后续会影响到数据库的写入，暂时隐了
#以下是产品描述信息栏内的信息获得，检索文字标签获得对应内容：
brand = response.xpath("//li[@id='J_attrBrandName']/text()").re('品牌:\xa0(.*?)$') #品牌
produce = response.xpath("//li[contains(text(),'产地')]/text()").re('产地:\xa0(.*?)$') #产地
effect = response.xpath("//li[contains(text(),'功效')]/text()").re('功效:\xa0(.*?)$') #功效
pat_id = 'id=(.*?)&'
this_id = re.compile(pat_id).findall(url)[0] pass
else: #淘宝
title = response.xpath("/html/head/title/text()").extract() #获取商品名称
#price = response.xpath("//em[@class = 'tb-rmb-num']/text()").extract()
#获取商品原价格-和上面保持一致
brand = response.xpath("//li[contains(text(),'品牌')]/text()").re('品牌:\xa0(.*?)$') #品牌
produce = response.xpath("//li[contains(text(),'产地')]/text()").re('产地:\xa0(.*?)$') #产地
effect = response.xpath("//li[contains(text(),'功效')]/text()").re('功效:\xa0(.*?)$') #功效
pat_id = 'id=(.*?)$'
this_id = re.compile(pat_id).findall(url)[0] pass
#抓取评论总数
comment_url = "https://rate.taobao.com/detailCount.do?callback=jsonp144&itemId="+str(this_id)
comment_data = urllib.request.urlopen(comment_url).read().decode('utf-8', 'ignore')
each_comment = '"count":(.*?)}'
comment = re.compile(each_comment).findall(comment_data)
item['title'] = title
item['link'] = url #item['price'] = price
item['now_price'] = response.meta['now_price']
item['comment'] = comment
item['address'] = response.meta['address']
item['sale_count'] = response.meta['sale_count']
item['brand']=brand
item['produce']=produce
item['effect']=effect
yield item2. settings.py配置
设置用户代理、不遵循robots.txt协议、取消Cookies。
# -*- coding: utf-8 -*-# Scrapy settings for taobao project## For simplicity, this file contains only settings considered important or# commonly used. You can find more settings consulting the documentation:## http://doc.scrapy.org/en/latest/topics/settings.html# http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html# http://scrapy.readthedocs.org/en/latest/topics/spider-middleware.htmlBOT_NAME = 'taobao'SPIDER_MODULES = ['taobao.spiders']
NEWSPIDER_MODULE = 'taobao.spiders'# Crawl responsibly by identifying yourself (and your website) on the user-agentUSER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:54.0) Gecko/20100101 Firefox/54.0' #设置用户代理值# Obey robots.txt rulesROBOTSTXT_OBEY = False #不遵循 robots.txt协议# Configure maximum concurrent requests performed by Scrapy (default: 16)CONCURRENT_REQUESTS = 100# Configure a delay for requests for the same website (default: 0)# See http://scrapy.readthedocs.org/en/latest/topics/settings.html#download-delay# See also autothrottle settings and docs# DOWNLOAD_DELAY = 0.25 #设置访问延迟# 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 #取消Cookies# 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 http://scrapy.readthedocs.org/en/latest/topics/spider-middleware.html#SPIDER_MIDDLEWARES = {# 'taobao.middlewares.TaobaoSpiderSpiderMiddleware': 543,#}# Enable or disable downloader middlewares# See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html#DOWNLOADER_MIDDLEWARES = {# 'taobao.middlewares.MyCustomDownloaderMiddleware': 543,#}# Enable or disable extensions# See http://scrapy.readthedocs.org/en/latest/topics/extensions.html#EXTENSIONS = {# 'scrapy.extensions.telnet.TelnetConsole': None,#}# Configure item pipelines# See http://scrapy.readthedocs.org/en/latest/topics/item-pipeline.htmlITEM_PIPELINES = { 'taobao.pipelines.TaobaoJsonPipeline':300 #导出文json文件
'taobao.pipelines.TaobaoPipeline':200 #导出至Mysql}# Enable and configure the AutoThrottle extension (disabled by default)# See http://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 http://scrapy.readthedocs.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'3.在items.py中添加存储容器对象
# -*- coding: utf-8 -*-# Define here the models for your scraped items## See documentation in:# http://doc.scrapy.org/en/latest/topics/items.htmlimport scrapyclass TaobaoItem(scrapy.Item): # define the fields for your item here like: # name = scrapy.Field() title = scrapy.Field() link = scrapy.Field() #price = scrapy.Field() comment = scrapy.Field() now_price = scrapy.Field() address = scrapy.Field() sale_count = scrapy.Field() brand = scrapy.Field() produce = scrapy.Field() effect = scrapy.Field() pass
第二步 将数据导出并存储至Mysql数据库
1. 将数据导出为json
在pipeline.py文件内写入如下内容，在setting.py文件中开启（详见settings.py）,
# -*- coding: utf-8 -*-import json
import codecsclass TaobaoJsonPipeline:
def __init__(self): self.file=codecs.open('taobao.json','w',encoding='utf-8') def process_item(self, item, spider):
lines = json.dumps(dict(item), ensure_ascii=False) + '\n'
self.file.write(lines) return item def close_spider(self, spider): self.file.close()运行爬虫，在终端输入
scrapy crawl tb --nolog
导出后文件自动存储在爬虫目录下：
屏幕快照 2018-07-20 下午9.02.19.png
2.将数据导出至MySQL
1）首先要先下载安装MySQL数据库
下载链接，dmg格式，一键安装。（安装过程中要求设置root用户的密码，选择普通加密，如果选高级加密的话后面会一直连接失败....）
设置完成后开启数据库：
屏幕快照 2018-07-20 下午9.07.37.png
可视化操作安装Workbentch，
Workbentch连接数据库，建立新的数据库，并新建表格并设置好字段：
屏幕快照 2018-07-22 下午8.53.15.png
2）在Python中安装pymysql包
cmd输入：conda install pymysql
或者直接用pip install pymysql
3）pipelines.py文件设置
这里数据库存储使用了异步操作，目的是防止插入数据的速度跟不上网页的爬取解析速度，造成阻塞。Python 中提供了 Twisted 框架来实现异步操作，该框架提供了一个连接池，通过连接池可以实现数据插入 MySQL 的异步化。详细教程参考Scrapy 入门笔记(4) --- 使用 Pipeline 保存数据
在pipeline.py文件中加入以下代码，并在setting.py中开启对应pipeline（详见settings.py）,
# -*- coding: utf-8 -*-import pymysqlimport pymysql.cursorsfrom twisted.enterprise import adbapiclass TaobaoPipeline(object):
#链接数据库
def __init__(self,):
dbparms = dict(
host='127.0.0.1',
db='数据库名称',
user='root',
passwd='数据库密码',
charset='utf8',
cursorclass=pymysql.cursors.DictCursor,
use_unicode=True,
) # 指定擦做数据库的模块名和数据库参数参数
self.dbpool = adbapi.ConnectionPool("pymysql", **dbparms) # 使用twisted将mysql插入变成异步执行
def process_item(self, item, spider):
query = self.dbpool.runInteraction(self.do_insert, item)
query.addErrback(self.handle_error, item, spider) #处理异常
#处理异步插入的异常
def handle_error(self, failure, item, spider):
print (failure)
#执行具体的插入
def do_insert(self, cursor, item):
#从item中导入
title = item['title'][0]
link = item['link'] #price = item['price'][0]
comment = item['comment'][0]
now_price = item['now_price']
address = item['address']
sale = item['sale_count']
brand=item['brand'][0]
produce=item['produce'][0]
effect = item['effect'][0]
print('商品标题\t', title)
print('商品链接\t', link) #print('商品原价\t', price)
print('商品现价\t', now_price)
print('商家地址\t', address)
print('评论数量\t', comment)
print('销量\t', sale)
print('品牌\t',brand)
print('产地\t',produce)
print('功效\t',effect) try:
sql="insert into taobaokh(title,link,comment,now_price,address,sale,brand,produce,effect) values(%s,%s,%s,%s,%s,%s,%s,%s,%s)"
values=(title,link,comment,now_price,address,sale,brand,produce,effect)
cursor.execute(sql,values)
print('导入成功')
print('------------------------------\n') return item except Exception as err: pass运行爬虫:
scrapy crawl tb --nolog
屏幕快照 2018-07-22 下午8.56.08.png
到此，爬虫基本已经可以正常运转起来了。
第三步 设置设置随机User-Agent
目的是每次请求时通过更换不同的user-agent，可以更好地伪装浏览器。
1.更新了源码的ua列表（PC端），添加到settings.py最后
USER_AGENT_LIST = [ "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36", "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/603.2.4 (KHTML, like Gecko) Version/10.1.1 Safari/603.2.4", "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36", "Mozilla/5.0 (Windows NT 10.0; WOW64; rv:54.0) Gecko/20100101 Firefox/54.0", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36", "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:54.0) Gecko/20100101 Firefox/54.0", "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:54.0) Gecko/20100101 Firefox/54.0", "Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36", "Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:54.0) Gecko/20100101 Firefox/54.0", "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36", "Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36", "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:54.0) Gecko/20100101 Firefox/54.0", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.79 Safari/537.36 Edge/14.14393", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.109 Safari/537.36", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/603.2.5 (KHTML, like Gecko) Version/10.1.1 Safari/603.2.5", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.104 Safari/537.36", "Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36 Edge/15.15063", "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36", "Mozilla/5.0 (Windows NT 6.3; WOW64; rv:54.0) Gecko/20100101 Firefox/54.0", "Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36", "Mozilla/5.0 (iPad; CPU OS 10_3_2 like Mac OS X) AppleWebKit/603.2.4 (KHTML, like Gecko) Version/10.0 Mobile/14F89 Safari/602.1", "Mozilla/5.0 (Windows NT 6.1; rv:54.0) Gecko/20100101 Firefox/54.0", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36", "Mozilla/5.0 (Windows NT 10.0; WOW64; rv:53.0) Gecko/20100101 Firefox/53.0", "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:53.0) Gecko/20100101 Firefox/53.0", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:54.0) Gecko/20100101 Firefox/54.0", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.109 Safari/537.36", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.109 Safari/537.36", "Mozilla/5.0 (X11; Linux x86_64; rv:54.0) Gecko/20100101 Firefox/54.0", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.104 Safari/537.36", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36", "Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0", "Mozilla/5.0 (Windows NT 6.1; Trident/7.0; rv:11.0) like Gecko", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/603.1.30 (KHTML, like Gecko) Version/10.1 Safari/603.1.30", "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:54.0) Gecko/20100101 Firefox/54.0", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.86 Safari/537.36", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36", "Mozilla/5.0 (Windows NT 5.1; rv:52.0) Gecko/20100101 Firefox/52.0", "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.109 Safari/537.36", "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Firefox/52.0", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.86 Safari/537.36", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/58.0.3029.110 Chrome/58.0.3029.110 Safari/537.36", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/603.2.5 (KHTML, like Gecko) Version/10.1.1 Safari/603.2.5", "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.104 Safari/537.36", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.104 Safari/537.36", "Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Firefox/45.0", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36", "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:53.0) Gecko/20100101 Firefox/53.0", "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.86 Safari/537.36", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.86 Safari/537.36", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.86 Safari/537.36 OPR/46.0.2597.32", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/59.0.3071.109 Chrome/59.0.3071.109 Safari/537.36", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:53.0) Gecko/20100101 Firefox/53.0", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36", "Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; rv:11.0) like Gecko", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36 OPR/45.0.2552.898", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36", "Mozilla/5.0 (Windows NT 10.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36", "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:40.0) Gecko/20100101 Firefox/40.1", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36 OPR/46.0.2597.39", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:54.0) Gecko/20100101 Firefox/54.0", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/601.7.7 (KHTML, like Gecko) Version/9.1.2 Safari/601.7.7", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_3) AppleWebKit/602.4.8 (KHTML, like Gecko) Version/10.0.3 Safari/602.4.8", "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36", "Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; Touch; rv:11.0) like Gecko", "Mozilla/5.0 (Windows NT 6.1; rv:52.0) Gecko/20100101 Firefox/52.0", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.106 Safari/537.36",
]
DOWNLOADER_MIDDLEWARES = { 'taobao.middlewares.ProcessHeaderMidware': 543,
}github上有人专门写了一个user-agent 的插件，也可以直接调用，链接
2.在middlewares.py文件里添加如下代码：
# encoding: utf-8from scrapy.utils.project import get_project_settingsimport random
settings = get_project_settings()class ProcessHeaderMidware():
"""process request add request info"""
def process_request(self, request, spider):
"""
随机从列表中获得header， 并传给user_agent进行使用
"""
ua = random.choice(settings.get('USER_AGENT_LIST'))
spider.logger.info(msg='now entring download midware') if ua:
request.headers['User-Agent'] = ua # Add desired logging message here.
spider.logger.info(u'User-Agent is : {} {}'.format(request.headers.get('User-Agent'), request)) pass设置完成。
第四步 使用Scrapy-redis实现分布式爬虫
为了进一步提高效率和防反爬虫能力，就要用到多进程和分布式爬虫了。
Scrapy-redis还有一个好处是支持断点续传，爬的过程中遇到过sracpy卡主住不动的情况，直接重新打开一个终端，输入爬虫指令，又继续跑起来~
1. Scrapy-redis环境搭建：
需要分别安装redis，scrapy-redis，和redis-py三个库：
1）redis
直接使用conda install redis安装（或pip install redis）
2） scrapy-redis
由于anaconda中没有scrapy-redis的安装包，需要下载第三方zip安装包，下载链接。安装过程：cmd依次输入
cd /Users/用户名/Downloads unzip scrapy-redis-master.zip -d/Users/用户名/Downloads/ #解压文件到指定路径cd scrapy-redis-master python setup.py install #安装文件password:***** #输入密码
如果不使用Anaconda，直接在终端pip install scrapy-redis应该也可以。
3） redis-py
装完redis之后，运行程序一直报错"ImportError: No module named redis"，搜过之后发现是Python默认不支持Redis，需要安装redis-py才能正常调用。下载链接
安装方法同上。
2.修改Scrapy项目文件
1）在settings.py中增加以下内容
SCHEDULER = "scrapy_redis.scheduler.Scheduler" #启用Redis调度存储请求队列SCHEDULER_PERSIST = True #不清除Redis队列、这样可以暂停/恢复 爬取DUPEFILTER_CLASS = "scrapy_redis.dupefilter.RFPDupeFilter" #确保所有的爬虫通过Redis去重SCHEDULER_QUEUE_CLASS = 'scrapy_redis.queue.SpiderPriorityQueue'REDIS_HOST = '127.0.0.1' # 也可以根据情况改成 localhostREDIS_PORT = 6379REDIS_URL = None
2）在items.py中增加以下内容
from scrapy.loader import ItemLoaderfrom scrapy.loader.processors import MapCompose, TakeFirst, Joinclass TaobaoSpiderLoader(ItemLoader): default_item_class = TaobaoItem default_input_processor = MapCompose(lambda s: s.strip()) default_output_processor = TakeFirst() description_out = Join()
3）对tb.py文件进行更改
import相关包：
from scrapy_redis.spiders import RedisSpider
修改TbSpider类：
class TbSpider(RedisSpider): name = 'tb' #allowed_domains = ['taobao.com'] #start_urls = ['http://taobao.com/'] redis_key = 'Taobao:start_urls'
配置完成！
3. 运行分布式爬虫
1）打开终端，启动redis服务器redis-server：
localhost:~ $ redis-server 3708:C 20 Jul 22:42:41.914 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo3708:C 20 Jul 22:42:41.915 # Redis version=4.0.10, bits=64, commit=00000000, modified=0, pid=3708, just started3708:C 20 Jul 22:42:41.915 # Warning: no config file specified, using the default config. In order to specify a config file use redis-server /path/to/redis.conf3708:M 20 Jul 22:42:41.916 * Increased maximum number of open files to 10032 (it was originally set to 256). _._ _.-``__ ''-._ _.-`` `. `_. ''-._ Redis 4.0.10 (00000000/0) 64 bit .-`` .-```. ```\/ _.,_ ''-._ ( ' , .-` | `, ) Running in standalone mode |`-._`-...-` __...-.``-._|'` _.-'| Port: 6379 | `-._ `._ / _.-' | PID: 3708 `-._ `-._ `-./ _.-' _.-' |`-._`-._ `-.__.-' _.-'_.-'| | `-._`-._ _.-'_.-' | http://redis.io `-._ `-._`-.__.-'_.-' _.-' |`-._`-._ `-.__.-' _.-'_.-'| | `-._`-._ _.-'_.-' | `-._ `-._`-.__.-'_.-' _.-' `-._ `-.__.-' _.-' `-._ _.-' `-.__.-' 3708:M 20 Jul 22:42:41.920 # Server initialized3708:M 20 Jul 22:42:41.920 * DB loaded from disk: 0.000 seconds 3708:M 20 Jul 22:42:41.920 * Ready to accept connections
看到这个界面就证明服务器开启，关掉窗口。
2）打开一个新的终端，运行爬虫：
scrapy crawl tb --nolog
此时爬虫处于等待状态，需要设置start_url。
3）再打开一个新的终端，输入：
redis-cli 127.0.0.1:6379>LPUSH Taobao:start_urls http://taobao.com (integer) 1
返回(integer) 1 则表示设置成功。（指令中的Taobao:start_urls对应tb.py文件中的设置redis_key = 'Taobao:start_urls'）
4）此时，爬虫开始运行....MacOS不会像windows一样，弹出多个终端，只在一个终端里跑，但明显速度加快了好多。
5）如果要中途停止爬虫，按ctrl+c。
停止后再输入 scrapy crawl taobao –nolog 运行的话，程序会断点续传，原因是在setting.py中设置了 SCHEDULER_PERSIST = True 。
如果想取消这个功能，要把True改为False。
6）爬取完毕后，要清除redis缓存
127.0.0.1:6379>flushdbok
完毕！
总结：
通过Python3.6和scrapy构建了一个淘宝商品的爬虫，通过scrapy-redis实现了分布式爬虫，最后用MySQL来存储数据。
问题
tmall链接下的商品原价格一直抓取失败，xpath在xpath finder验证可行，运行后一直是空值，猜测可能是网页有异步加载，待研究。
tmall链接抓取过程中，很多链接进行了重定向（301、302）导致数据无法抓取，应该是跳转登录之类的反爬措施。
（声明：此文章仅作为学习交流，不做为其它用途）
作者：小蕊子0409
链接：https://www.jianshu.com/p/77d8fb64cbcd
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