Python爬虫爬取百度搜索内容代码实例

# coding=utf8
import urllib2
import string
import urllib
import re
import random
#设置多个user_agents，防止百度限制IP
user_agents = ['Mozilla/5.0 (Windows NT 6.1; WOW64; rv:23.0) Gecko/20130406 Firefox/23.0', 
  'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:18.0) Gecko/20100101 Firefox/18.0', 
  'Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/533+ 
  (KHTML, like Gecko) Element Browser 5.0', 
  'IBM WebExplorer /v0.94', 'Galaxy/1.0 [en] (Mac OS X 10.5.6; U; en)', 
  'Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0)', 
  'Opera/9.80 (Windows NT 6.0) Presto/2.12.388 Version/12.14', 
  'Mozilla/5.0 (iPad; CPU OS 6_0 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) 
  Version/6.0 Mobile/10A5355d Safari/8536.25', 
  'Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) 
  Chrome/28.0.1468.0 Safari/537.36', 
  'Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.0; Trident/5.0; TheWorld)']
def baidu_search(keyword,pn):
 p= {'wd': keyword} 
 res=urllib2.urlopen(("http://www.baidu.com/s"+urllib.urlencode(p)+"&pn={0}&cl=3&rn=100").format(pn))
 html=res.read()
 return html
def getList(regex,text):
 arr = []
 res = re.findall(regex, text)
 if res:
  for r in res:
   arr.append(r)
 return arr
def getMatch(regex,text):
 res = re.findall(regex, text)
 if res:
  return res[0]
 return ""
def clearTag(text):
 p = re.compile(u'<[^>]+>')
 retval = p.sub("",text)
 return retval
def geturl(keyword):
 for page in range(10):
  pn=page*100+1
  html = baidu_search(keyword,pn)
  content = unicode(html, 'utf-8','ignore')
  arrList = getList(u"<table.*"result".*?>.*", content)
  for item in arrList:
   regex = u"<h3.*"t".*?><a.*"(.*" rel="external nofollow" rel="external nofollow" .*?>(.*"
   link = getMatch(regex,item)
   url = link[0]
   #获取标题
   #title = clearTag(link[1]).encode('utf8')
   try:
    domain=urllib2.Request(url)
    r=random.randint(0,11)
    domain.add_header('User-agent', user_agents[r])
    domain.add_header('connection','keep-alive')
    response=urllib2.urlopen(domain)
    uri=response.geturl()
    print uri
   except:
    continue
if __name__=='__main__':
 geturl('python')</a.*&#63;href="(.*" rel="external nofollow" rel="external nofollow" .*?></h3.*"t".*?></table.*"result".*?>