python实现百度关键词排名查询

就是一个简单的python查询百度关键词排名的函数，以下是一些简介：
1、ua随机
2、操作简单方便，直接getrank(关键词，域名)就可以了
3、编码转化。编码方面应该没啥问题了。
4、结果丰富。不仅有排名，还有搜索结果的title，url，快照时间，符合seo需求
5、拿来做个软件或者自己用都很方便。

功能是单线程实现，速度慢，大家可以参考修改成自己需要的。

#coding=utf-8

import requests
import beautifulsoup
import re
import random

def decodeanyword(w):
    try:
        w.decode('utf-8')
    except:
        w = w.decode('gb2312')
    else:
        w = w.decode('utf-8')
    return w

def createurl(checkword):   #create baidu url with search words
    checkword = checkword.strip()
    checkword = checkword.replace(' ', '+').replace('\n', '')
    baiduurl = 'http://www.baidu.com/s?wd=%s&rn=100' % checkword
    return baiduurl

def getcontent(baiduurl):   #get the content of the serp
    ualist = ['mozilla/4.0+(compatible;+msie+6.0;+windows+nt+5.1;+sv1;+.net+clr+1.1.4322;+tencenttraveler)',
    'mozilla/4.0+(compatible;+msie+6.0;+windows+nt+5.1;+sv1;+.net+clr+2.0.50727;+.net+clr+3.0.4506.2152;+.net+clr+3.5.30729)',
    'mozilla/5.0+(windows+nt+5.1)+applewebkit/537.1+(khtml,+like+gecko)+chrome/21.0.1180.89+safari/537.1',
    'mozilla/4.0+(compatible;+msie+6.0;+windows+nt+5.1;+sv1)',
    'mozilla/5.0+(windows+nt+6.1;+rv:11.0)+gecko/20100101+firefox/11.0',
    'mozilla/4.0+(compatible;+msie+8.0;+windows+nt+5.1;+trident/4.0;+sv1)',
    'mozilla/4.0+(compatible;+msie+8.0;+windows+nt+5.1;+trident/4.0;+gtb7.1;+.net+clr+2.0.50727)',
    'mozilla/4.0+(compatible;+msie+8.0;+windows+nt+5.1;+trident/4.0;+kb974489)']
    headers = {'user-agent': random.choice(ualist)}

    r = requests.get(baiduurl, headers = headers)
    return r.content

def getlasturl(rawurl): #get final url while there're redirects
    r = requests.get(rawurl)
    return r.url

def getatext(atext):    #get the text with <a> and </a>
    pat = re.compile(r'<a .*?>(.*?)</a>')
    match = pat.findall(atext.replace('\n', ''))
    puretext = match[0].replace('<em>', '').replace('</em>', '')
    return puretext.replace('\n', '')

def getcachedate(t):    #get the date of cache
    pat = re.compile(r'<span class="g">.*?(\d{4}-\d{1,2}-\d{1,2}) </span>')
    match = pat.findall(t)
    cachedate = match[0]
    return cachedate

def getrank(checkword, domain): #main line
    checkword = checkword.replace('\n', '')
    checkword = decodeanyword(checkword)
    baiduurl = createurl(checkword)
    cont = getcontent(baiduurl)
    soup = beautifulsoup.beautifulsoup(cont)
    results = soup.findall('table', {'class': 'result'})    #find all results in this page

    for result in results:
        checkdata = unicode(result.find('span', {'class': 'g'}))
        if re.compile(r'^[^/]*%s.*?' %domain).match(checkdata.replace('<b>', '').replace('</b>', '')): #改正则
            nowrank = result['id']  #get the rank if match the domain info

            reslink = result.find('h3').a
            resurl = reslink['href']
            domainurl = getlasturl(resurl)  #get the target url
            restitle = getatext(unicode(reslink))   #get the title of the target page

            rescache = result.find('span', {'class': 'g'})
            cachedate = getcachedate(unicode(rescache)) #get the cache date of the target page

            res = u'%s, 第%s名, %s, %s, %s' % (checkword, nowrank, restitle, cachedate, domainurl)
            return res.encode('gb2312')
            break
    else:
        return '>100'

domain = 'www.baidu.com' #set the domain which you want to search.
print getrank('百度', domain)