原文地址： http://www.liuyu.live/blog/content?aid=69
知乎爬虫没有什么太大问题，最大的反爬（至少当时我爬的时候），就是对频率限制，所以在中间件哪里增加了切换IP功能。
然后我之前在B站直播过，所以具体流程就用视频说话：
链接地址：https://www.bilibili.com/video/av20220465?from=search&seid=14020024976425984810
这里是代码：
items.py
# -*- coding: utf-8 -*-
# Define here the models for your scraped items
#
# See documentation in:
# http://doc.scrapy.org/en/latest/topics/items.html
importscrapy
classZhihuItem(scrapy.Item):
# define the fields for your item here like:
# name = scrapy.Field()
name =scrapy.Field()
url_token =scrapy.Field()
headline =scrapy.Field()
follower_count =scrapy.Field()
answer_count =scrapy.Field()
articles_count =scrapy.Field()
uid =scrapy.Field()
gender =scrapy.Field()
type=scrapy.Field()
spider.py
# -*- coding: utf-8 -*-
importscrapy
importjson
importre
fromzhihu.items importZhihuItem
fromscrapy_redis.spiders importRedisCrawlSpider
classUserinforSpider(RedisCrawlSpider):
name ="userinfor"
redis_key ='myspider:start_urls'
allowed_domains =["zhihu.com"]
# start_urls = ['https://www.zhihu.com/api/v4/members/liuyu-43-97/followers?include=data%5B*%5D.answer_count%2Carticles_count%2Cgender%2Cfollower_count%2Cis_followed%2Cis_following%2Cbadge%5B%3F(type%3Dbest_answerer)%5D.topics&offset=20&limit=20']
defparse(self, response):
temp_data =json.loads(response.body.decode("utf-8"))["data"]
count =len(temp_data)
ifcount < 20:
pass
else:
page_offset =int(re.findall("&offset=(.*?)&", response.url)[0])
new_page_offset =page_offset +20
next_page_url =response.url.replace("&offset="+str(page_offset) +"&", "&offset="+str(new_page_offset) +"&")
yieldscrapy.Request(url=next_page_url, callback=self.parse)
foreve_user intemp_data:
item =ZhihuItem()
item['name'] =eve_user['name']
item['url_token'] =eve_user['url_token']
item['headline'] =eve_user['headline']
item['follower_count'] =eve_user['follower_count']
item['answer_count'] =eve_user['answer_count']
item['articles_count'] =eve_user['articles_count']
item['uid'] =eve_user['id']
item['gender'] =eve_user['gender']
item['type'] =eve_user['type']
with open("userinfor.txt") as f:
user_list =f.read()
ifeve_user['url_token'] notinuser_list:
with open("userinfor.txt", "a") as f:
f.write(eve_user['url_token'] +"----")
yielditem
new_url ="https://www.zhihu.com/api/v4/members/"+eve_user['url_token'] +"/followers?include=data%5B*%5D.answer_count%2Carticles_count%2Cgender%2Cfollower_count%2Cis_followed%2Cis_following%2Cbadge%5B%3F(type%3Dbest_answerer)%5D.topics&offset=20&limit=20"
yieldscrapy.Request(url=new_url, callback=self.parse)
settings.py
# Scrapy settings for zhihu 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.html
BOT_NAME ='zhihu'
SPIDER_MODULES =['zhihu.spiders']
NEWSPIDER_MODULE ='zhihu.spiders'
MONGODB_HOST ='127.0.0.1'
MONGODB_PORT =27017
MONGODB_DBNAME ='zhihu'
MONGODB_DOCNAME ='userinfor'
# Crawl responsibly by identifying yourself (and your website) on the user-agent
USER_AGENT ='Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.186 Safari/537.36'
# Obey robots.txt rules
ROBOTSTXT_OBEY =False
# Configure maximum concurrent requests performed by Scrapy (default: 16)
# CONCURRENT_REQUESTS = 32
# 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 = 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": 'application/json, text/plain, */*',
"Accept-Language": 'zh-CN,zh;q=0.9,en;q=0.8',
"authorization": 'oauth c3cef7c66a1843f8b3a9e6a1e3160e20',
"Cache-Control": 'no-cache',
"Connection": 'keep-alive',
"Cookie": '_zap=74a1bc89-5927-46f1-a903-26b9d4f9906c; q_c1=679bbf981bc54edaa36a718a757d7110|1506423740000|1502849291000; d_c0="AFBCMYYIigyPTn-w9gPOx5CNrckgcsQKrhk=|1508201688"; q_c1=f3521e394ce8459094ba76547cddd3e5|1517535767000|1502849291000; aliyungf_tc=AQAAACykS2tz0ggA5KAxJPLJJw8rf8SF; _xsrf=c8e59c5f-190a-4b71-ad56-1425517c7a9b; r_cap_id="Yjc3Y2Y1ODkxYzcxNGZkOGFhMDUwZjBhNjFhZTEyYjI=|1519810983|a19b0558ddd2a119ed7581c8fd59427ab2298d03"; cap_id="ZDM1Y2UzZTBhZTQ2NDc3OWIzYmE3YzczYmY0YmVlNzE=|1519810983|4c6504306036f99443b659ce4f8ea2723ebb6a96"; l_cap_id="NDcyOGU5YzUyNTdmNDc1OTlhMGU1Mzc3MjQ4NDY5YjI=|1519810983|ed1d25b9a6905ad1891a94984d8cecd51b8a96e0"; __utma=51854390.1002977338.1508201688.1516880301.1519810987.10; __utmc=51854390; __utmz=51854390.1519810987.10.10.utmcsr=zhihu.com|utmccn=(referral)|utmcmd=referral|utmcct=/people/liuyu-43-97/activities; __utmv=51854390.000--|2=registration_date=20160118=1^3=entry_date=20170816=1; capsion_ticket="2|1:0|10:1519878553|14:capsion_ticket|44:N2NhNTJmNGQ5M2EyNDUzODk1MzIxYjgzNjFkM2FiZmY=|6b0b25b31dbdc0c80f49a9db073ec4953c5c4f6edd1bb1978bcee89c9b64f0b9"',
"Host": 'www.zhihu.com',
"Pragma": 'no-cache',
"Referer": 'https://www.zhihu.com/',
"X-UDID": 'AFBCMYYIigyPTn-w9gPOx5CNrckgcsQKrhk=',
}
# Enable or disable spider middlewares
# See http://scrapy.readthedocs.org/en/latest/topics/spider-middleware.html
# SPIDER_MIDDLEWARES = {
# 'zhihu.middlewares.ZhihuSpiderMiddleware': 543,
# }
# Enable or disable downloader middlewares
# See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html
DOWNLOADER_MIDDLEWARES ={
# 'zhihu.middlewares.MyCustomDownloaderMiddleware': 543,
'zhihu.middlewares.ChangeProxy': 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.html
ITEM_PIPELINES ={
'zhihu.pipelines.ZhihuPipeline': 300,
}
# 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'
SCHEDULER ="scrapy_redis.scheduler.Scheduler"
DUPEFILTER_CLASS ="scrapy_redis.dupefilter.RFPDupeFilter"
SCHEDULER_PERSIST =True
SCHEDULER_QUEUE_CLASS ='scrapy_redis.queue.SpiderQueue'
middlewares.py
# -*- coding: utf-8 -*-
# Define here the models for your spider middleware
#
# See documentation in:
# http://doc.scrapy.org/en/latest/topics/spider-middleware.html
fromscrapy importsignals
importrequests
importjson
classZhihuSpiderMiddleware(object):
# Not all methods need to be defined. If a method is not defined,
# scrapy acts as if the spider middleware does not modify the
# passed objects.
@classmethod
deffrom_crawler(cls, crawler):
# This method is used by Scrapy to create your spiders.
s =cls()
crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
returns
defprocess_spider_input(response, spider):
# Called for each response that goes through the spider
# middleware and into the spider.
# Should return None or raise an exception.
returnNone
defprocess_spider_output(response, result, spider):
# Called with the results returned from the Spider, after
# it has processed the response.
# Must return an iterable of Request, dict or Item objects.
fori inresult:
yieldi
defprocess_spider_exception(response, exception, spider):
# Called when a spider or process_spider_input() method
# (from other spider middleware) raises an exception.
# Should return either None or an iterable of Response, dict
# or Item objects.
pass
defprocess_start_requests(start_requests, spider):
# Called with the start requests of the spider, and works
# similarly to the process_spider_output() method, except
# that it doesn’t have a response associated.
# Must return only requests (not items).
forr instart_requests:
yieldr
defspider_opened(self, spider):
spider.logger.info('Spider opened: %s'%spider.name)
classChangeProxy(object):
'''
需要思考的几个问题：
1）什么时候需要切换IP
本身的IP被ban，被拉黑了，无法继续使用该IP请求目标网站了
2）切换ip是否需要支出
（一般需要购买）免费的IP，不需要花钱，不免费的IP，需要花钱，但是，大部分绝大部分很大一部分的免费IP是不能用
3）如何更优秀的切换IP
A）代理IP给我们的API，是有一个请求限制的，例如有的限制3S，有的限制5S，还有的限制1S
B）可能我们的一个代理IP获得之后，很快就会失效了，所以，一般情况下，代理IP都是先验证，后使用
C）很有可能一个代理IP，我们可以访问网页多次，才会被ban
I）我们一次获得多少代理IP？
小批量多次获取
II）我们一个代理IP用多少次，再切换
完善代理IP切换功能要考虑的几个问题：
1）IP是否可用
2）IP用几次清除掉
3）每次获得多少IP
1 2 3(不可用) 4 5 6 7 8 9 10
'''
def__init__(self):
'''
初始化变量
get_url 是请求的api
temp_url 是验证的地址
ip_list 是ip
'''
self.get_url ="http://api.xdaili.cn/xdaili-api//greatRecharge/getGreatIp?spiderId=e805d7cd7baa41ef87dfc5cec0ed9614&orderno=YZ20173293618kDUVrD&returnType=2&count=10"
self.temp_url ="http://ip.chinaz.com/getip.aspx"
self.ip_list =[]
# 用来记录使用ip的个数，或者是目前正在使用的是第几个IP,本程序，我一次性获得了10个ip，所以count最大默认为9
self.count =0
# 用来记录每个IP的使用次数,此程序，我设置为最大使用4次换下一个ip
self.evecount =0
defgetIPData(self):
'''
这部分是获得ip，并放入ip池（先清空原有的ip池）
:return:
'''
temp_data =requests.get(url=self.get_url).text
self.ip_list.clear()
foreve_ip injson.loads(temp_data)["RESULT"]:
print(eve_ip)
self.ip_list.append({
"ip":eve_ip["ip"],
"port":eve_ip["port"]
})
defchangeProxy(self,request):
'''
修改代理ip
:param request: 对象
:return:
'''
request.meta["proxy"] ="http://"+str(self.ip_list[self.count-1]["ip"]) +":"+str(self.ip_list[self.count-1]["port"])
defyanzheng(self):
'''
验证代理ip是否可用，默认超时5s
:return:
'''
requests.get(url=self.temp_url,proxies={"http":str(self.ip_list[self.count-1]["ip"]) +":"+str(self.ip_list[self.count-1]["port"])},timeout=5)
defifUsed(self,request):
'''
切换代理ip的跳板
:param request:对象
:return:
'''
try:
self.changeProxy(request)
self.yanzheng()
except:
ifself.count ==0orself.count ==10:
self.getIPData()
self.count =1
self.evecount =0
self.count =self.count +1
self.ifUsed(request)
defprocess_request(self, request, spider):
ifself.count ==0orself.count==10:
self.getIPData()
self.count =1
ifself.evecount ==80:
self.count =self.count +1
self.evecount =0
else:
self.evecount =self.evecount +1
self.ifUsed(request)
pipelines.py
# -*- coding: utf-8 -*-
# Define your item pipelines here
#
# Don't forget to add your pipeline to the ITEM_PIPELINES setting
# See: http://doc.scrapy.org/en/latest/topics/item-pipeline.html
fromscrapy.conf importsettings
importpymongo
classZhihuPipeline(object):
def__init__(self):
host =settings['MONGODB_HOST']
port =settings['MONGODB_PORT']
dbName =settings['MONGODB_DBNAME']
client =pymongo.MongoClient(host=host,port=port)
tdb =client[dbName]
self.post =tdb[settings['MONGODB_DOCNAME']]
defprocess_item(self, item, spider):
zhihu =dict(item)
self.post.insert(zhihu)
returnitem
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