用BeautifulSoup爬百度贴吧帖子内容

# coding=utf-8
import urllib2
from bs4 import BeautifulSoup
class BDTB:
    def __init__(self,baseurl,seeLZ,floorTag):
        self.baseurl=baseurl
        self.seeLZ='?see_lz='+str(seeLZ)
        self.file=None
        self.floor=1
        self.floorTag=floorTag
        self.defaultTitle=u"百度贴吧"
    def getpage(self,pagenum):
        try:
            url = self.baseurl + self.seeLZ + '&pn=' + str(pagenum)
            request = urllib2.Request(url)
            response = urllib2.urlopen(request)
            page = BeautifulSoup(response, "html5lib")
            return page
        except urllib2.URLError,e:
            if hasattr(e,'reason'):
                print u"连接百度贴吧失败，错误原因",e.reason
                return None

    def getTitle(self):
        page=self.getpage(1)
        tag=page.h3
        title=tag['title']
        print title
        return title

    def getPageNum(self):
        page=self.getpage(1)
        num=page.find_all(attrs={"class":"red"})
        pagenum=num[1].string
        return int(pagenum)

    def getcontent(self):
        pagenum=self.getPageNum()+1
        contents=[]
        for num in range(1,pagenum):
            page = self.getpage(num)
            num = page.find_all('cc')
            for item in num:
                content=item.get_text()
                contents.append(content.encode('utf-8'))
        return contents

    def getFileTitle(self):
        title=self.getTitle()
        if title is not None:
            self.file=open(title+".txt","w+")
        else:
            self.file=open(self.defaultTitle+".txt","w+")

    def writeData(self):
        contents=self.getcontent()
        for item in contents:
            if self.floorTag =='1':
                floorLine='\n'+str(self.floor)+u'---------------------------------------------\n'
                self.file.write(floorLine)
            self.file.write(item)
            self.floor +=1

    def start(self):
        self.getFileTitle()
        pagenum=self.getPageNum()
        if pagenum == None:
            print "URL已失效，请重试"
            return
        try:
            print "该帖子共有"+str(pagenum)+"页"
            self.writeData()
        except IOError,e:
            print "写入异常，原因"+e.message
        finally:
            print "写入成功"

print u"请输入帖子代号"
baseurl='http://tieba.baidu.com/p/'+str(raw_input(u'http://tieba.baidu.com/p/'))
seeLZ=raw_input("是否只获取楼主发言，是输入1，否输入0\n")
floorTag=raw_input("是否写入楼层信息，是输入1否输入0\n")
bdtb=BDTB(baseurl,seeLZ,floorTag)
bdtb.start()