【python爬虫】获取百度贴吧帖子的python脚本

# -*- coding:utf-8 -*-
import urllib
import urllib2
import re


class Tool:
    removeImg = re.compile('<img.*?>| {7}|')
    removeAddr = re.compile('<a.*?>|</a>')
    replaceLine = re.compile('<tr>|<div>|</div>|</p>')
    replaceTD = re.compile('<td>')
    replacePara = re.compile('<p.*?>')
    replaceBR = re.compile('<br><brr>|<br>')
    removeExtraTag = re.compile('<.*?>')
    removeSpace = re.compile('&nbsp;')
    def replace(self,x):
        x = re.sub(self.removeImg,"",x)
        x = re.sub(self.removeAddr,"",x)
        x = re.sub(self.replaceLine,"\n",x)
        x = re.sub(self.replaceTD,"\t",x)
        x = re.sub(self.replacePara,"\n    ",x)
        x = re.sub(self.replaceBR,"\n",x)
        x = re.sub(self.removeExtraTag,"",x)
        x = re.sub(self.removeSpace," ",x)
        return x.strip()




class BDTB:
    def __init__(self,baseURL,seeLZ,floorTag):
        self.baseURL = baseURL
        self.seeLZ = '?see_lz='+str(seeLZ)
        self.tool = Tool()
        self.file = None
        self.floor = 1
        self.defaultTitle = u"百度贴吧" #默认的标题，如果没有成功获取到标题的话则会用这个标题
        self.floorTag = floorTag

    def getPage(self,pageNum):
        try:
            url = self.baseURL+self.seeLZ + '&pn=' + str(pageNum)
            request = urllib2.Request(url)
            response = urllib2.urlopen(request)
            return response.read().decode('utf-8')

        except urllib2.URLError,e:
            if hasattr(e,"reason"):
                print "fail to connect,reason:",e.reason
                return None
    def getTitle(self,page):
        pattern = re.compile('class="core_title_txt pull-left text-overflow  " title="(.*?)" style="',re.S)
        result = re.search(pattern,page)
        if result:
            return result.group(1).strip()
        else:
            return None

    def getPageNum(self,page):
        pattern = re.compile('<li class="l_reply_num".*?>*?</span>.*?<span.*?>(.*?)</span>')
        result = re.search(pattern,page)
        if result:
            return result.group(1).strip()
        else:
            return None

    def getContent(self,page):
        pattern = re.compile(ur'<div id="post_content_.*?>(.*?)</div>.*?<span class="tail-info">.*?[\u697c]</span><span class="tail-info">(.*?)</span></div>',re.S)
        items = re.findall(pattern,page)
        pattern_author=re.compile('alog-group="p_author".*?target="_blank">(.*?)</a>')
        authors=re.findall(pattern_author,page)
        contents = []
        p=0
        for item in items:
            content = "\n"+self.tool.replace(item[0])+"\n"
            date="\n"+item[1]+"\n"
            dataX=content+date+authors[p]
            contents.append(dataX.encode('utf-8'))
            p=p+1
        return contents



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


    def writeData(self,contents):
        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):
        indexPage = self.getPage(1)
        pageNum = self.getPageNum(indexPage)
        title = self.getTitle(indexPage)
        self.setFileTitle(title)
        if pageNum == None:
            print "URL已失效，请重试"
            return
        try:
            print "该帖子共有" + str(pageNum) + "页"
            for i in range(1,int(pageNum)+1):
                print "正在写入第" + str(i) + "页数据"
                page = self.getPage(i)
                contents = self.getContent(page)
                self.writeData(contents)
        except IOError,e:
            print "写入异常，原因：" + e.message
        finally:
            print "写入任务完成！！！"




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()