python实现提取百度搜索结果的方法

# coding=utf8
import urllib2
import string
import urllib
import re
import random
#设置多个user_agents，防止百度IP
user_agents = ['Mozilla/5.0 (Windows NT 6.1; WOW; rv:23.0) Gecko/20130406 Firefox/23.0', 
 'Mozilla/5.0 (Windows NT 6.1; WOW; 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; WOW; 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".*?", content)
 for item in arrList:
 regex = u"(.*?)"
 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')