Python爬取大量数据时，如何防止IP被封 !这点非常重要

继续老套路，这两天我爬取了猪八戒上的一些数据 网址是：http://task.zbj.com/t-ppsj/p1s5.html，可能是由于爬取的数据量有点多吧，结果我的IP被封了，需要自己手动来验证解封ip,但这显然阻止了我爬取更多的数据了。

私信小编01 获取源代码！

下面是我写的爬取猪八戒的被封IP的代码

# coding=utf-8
import requests
from lxml import etree
def getUrl():
 for i in range(33):
 url = 'http://task.zbj.com/t-ppsj/p{}s5.html'.format(i+1)
 spiderPage(url)
def spiderPage(url):
 if url is None:
 return None
 htmlText = requests.get(url).text
 selector = etree.HTML(htmlText)
 tds = selector.xpath('//*[@class="tab-switch tab-progress"]/table/tr')
 try:
 for td in tds:
 price = td.xpath('./td/p/em/text()')
 href = td.xpath('./td/p/a/@href')
 title = td.xpath('./td/p/a/text()')
 subTitle = td.xpath('./td/p/text()')
 deadline = td.xpath('./td/span/text()')
 price = price[0] if len(price)>0 else '' # Python的三目运算 :为真时的结果 if 判定条件 else 为假时的结果
 title = title[0] if len(title)>0 else ''
 href = href[0] if len(href)>0 else ''
 subTitle = subTitle[0] if len(subTitle)>0 else ''
 deadline = deadline[0] if len(deadline)>0 else ''
 print price,title,href,subTitle,deadline
 print '---------------------------------------------------------------------------------------'
 spiderDetail(href)
 except:
 print '出错'
def spiderDetail(url):
 if url is None:
 return None
 try:
 htmlText = requests.get(url).text
 selector = etree.HTML(htmlText)
 aboutHref = selector.xpath('//*[@id="utopia_widget_10"]/div[1]/div/div/div/p[1]/a/@href')
 price = selector.xpath('//*[@id="utopia_widget_10"]/div[1]/div/div/div/p[1]/text()')
 title = selector.xpath('//*[@id="utopia_widget_10"]/div[1]/div/div/h2/text()')
 contentDetail = selector.xpath('//*[@id="utopia_widget_10"]/div[2]/div/div[1]/div[1]/text()')
 publishDate = selector.xpath('//*[@id="utopia_widget_10"]/div[2]/div/div[1]/p/text()')
 aboutHref = aboutHref[0] if len(aboutHref) > 0 else '' # python的三目运算 :为真时的结果 if 判定条件 else 为假时的结果
 price = price[0] if len(price) > 0 else ''
 title = title[0] if len(title) > 0 else ''
 contentDetail = contentDetail[0] if len(contentDetail) > 0 else ''
 publishDate = publishDate[0] if len(publishDate) > 0 else ''
 print aboutHref,price,title,contentDetail,publishDate
 except:
 print '出错'
if '_main_':
 getUrl()

我发现代码运行完后，后面有几页数据没有被爬取，我再也没有办法去访问猪八戒网站了，等过了一段时间才能去访问他们的网站，这就很尴尬了，我得防止被封IP

如何防止爬取数据的时候被网站封IP这里有一些套路.查了一些套路

1.修改请求头

之前的爬虫代码没有添加头部，这里我添加了头部，模拟成浏览器去访问网站

 user_agent = 'Mozilla/5.0 (windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.104 Safari/537.36 Core/1.53.4295.400'
 headers = {'User-Agent': user_agent}
 htmlText = requests.get(url, headers=headers, proxies=proxies).text

2.采用代理IP

当自己的ip被网站封了之后，只能采用代理ip的方式进行爬取，所以每次爬取的时候尽量用代理ip来爬取，封了代理还有代理。

这里我引用了这个博客的一段代码来生成ip地址:http://blog.csdn.net/lammonpeter/article/details/52917264

生成代理ip,大家可以直接把这个代码拿去用

# coding=utf-8
# IP地址取自国内髙匿代理IP网站：http://www.xicidaili.com/nn/
# 仅仅爬取首页IP地址就足够一般使用
from bs4 import BeautifulSoup
import requests
import random
def get_ip_list(url, headers):
 web_data = requests.get(url, headers=headers)
 soup = BeautifulSoup(web_data.text, 'lxml')
 ips = soup.find_all('tr')
 ip_list = []
 for i in range(1, len(ips)):
 ip_info = ips[i]
 tds = ip_info.find_all('td')
 ip_list.append(tds[1].text + ':' + tds[2].text)
 return ip_list
def get_random_ip(ip_list):
 proxy_list = []
 for ip in ip_list:
 proxy_list.append('http://' + ip)
 proxy_ip = random.choice(proxy_list)
 proxies = {'http': proxy_ip}
 return proxies
if __name__ == '__main__':
 url = 'http://www.xicidaili.com/nn/'
 headers = {
 'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.143 Safari/537.36'
 }
 ip_list = get_ip_list(url, headers=headers)
 proxies = get_random_ip(ip_list)
 print(proxies)

好了我用上面的代码给我生成了一批ip地址（有些ip地址可能无效，但只要不封我自己的ip就可以了,哈哈），然后我就可以在我的请求头部添加ip地址

** 给我们的请求添加代理ip**

 proxies = {
 'http': 'http://124.72.109.183:8118',
 'http': 'http://49.85.1.79:31666'
 }
 user_agent = 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.104 Safari/537.36 Core/1.53.4295.400'
 headers = {'User-Agent': user_agent}
 htmlText = requests.get(url, headers=headers, timeout=3, proxies=proxies).text

目前知道的就

最后完整代码如下：

# coding=utf-8
import requests
import time
from lxml import etree
def getUrl():
 for i in range(33):
 url = 'http://task.zbj.com/t-ppsj/p{}s5.html'.format(i+1)
 spiderPage(url)
def spiderPage(url):
 if url is None:
 return None
 try:
 proxies = {
 'http': 'http://221.202.248.52:80',
 }
 user_agent = 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.104 Safari/537.36 Core/1.53.4295.400'
 headers = {'User-Agent': user_agent}
 htmlText = requests.get(url, headers=headers,proxies=proxies).text
 selector = etree.HTML(htmlText)
 tds = selector.xpath('//*[@class="tab-switch tab-progress"]/table/tr')
 for td in tds:
 price = td.xpath('./td/p/em/text()')
 href = td.xpath('./td/p/a/@href')
 title = td.xpath('./td/p/a/text()')
 subTitle = td.xpath('./td/p/text()')
 deadline = td.xpath('./td/span/text()')
 price = price[0] if len(price)>0 else '' # python的三目运算 :为真时的结果 if 判定条件 else 为假时的结果
 title = title[0] if len(title)>0 else ''
 href = href[0] if len(href)>0 else ''
 subTitle = subTitle[0] if len(subTitle)>0 else ''
 deadline = deadline[0] if len(deadline)>0 else ''
 print price,title,href,subTitle,deadline
 print '---------------------------------------------------------------------------------------'
 spiderDetail(href)
 except Exception,e:
 print '出错',e.message
def spiderDetail(url):
 if url is None:
 return None
 try:
 htmlText = requests.get(url).text
 selector = etree.HTML(htmlText)
 aboutHref = selector.xpath('//*[@id="utopia_widget_10"]/div[1]/div/div/div/p[1]/a/@href')
 price = selector.xpath('//*[@id="utopia_widget_10"]/div[1]/div/div/div/p[1]/text()')
 title = selector.xpath('//*[@id="utopia_widget_10"]/div[1]/div/div/h2/text()')
 contentDetail = selector.xpath('//*[@id="utopia_widget_10"]/div[2]/div/div[1]/div[1]/text()')
 publishDate = selector.xpath('//*[@id="utopia_widget_10"]/div[2]/div/div[1]/p/text()')
 aboutHref = aboutHref[0] if len(aboutHref) > 0 else '' # python的三目运算 :为真时的结果 if 判定条件 else 为假时的结果
 price = price[0] if len(price) > 0 else ''
 title = title[0] if len(title) > 0 else ''
 contentDetail = contentDetail[0] if len(contentDetail) > 0 else ''
 publishDate = publishDate[0] if len(publishDate) > 0 else ''
 print aboutHref,price,title,contentDetail,publishDate
 except:
 print '出错'
if '_main_':
 getUrl()

数据全部爬取出来了，且我的IP也没有被封。当然防止被封IP肯定不止这些了，这还需要进一步探索!

最后

虽然数据我是已经抓取过来了，但是我的数据都没有完美呈现出来，只是呈现在我的控制台上，这并不完美，我应该写入execl文件或者数据库中啊，这样才能方便采用。所以接下来我准备了使用Python操作execl