python爬虫实战2-百度贴吧

转载自http://cuiqingcai.com/993.html
亲测好用
简直太强大了，目前可以做到爬任何一个帖子，
以后任何网站都可以爬了啊，爽

# -*- coding:utf-8 -*-import urllibimport urllib2import re# 处理页面标签类class Tool:    # 去除img标签,7位长空格    removeImg = re.compile('<img.*?>| {7}|')    # 删除超链接标签    removeAddr = re.compile('<a.*?>|</a>')    # 把换行的标签换为\n    replaceLine = re.compile('<tr>|<div>|</div>|</p>')    # 将表格制表<td>替换为\t    replaceTD = re.compile('<td>')    # 把段落开头换为\n加空两格    replacePara = re.compile('<p.*?>')    # 将换行符或双换行符替换为\n    replaceBR = re.compile('<br><br>|<br>')    # 将其余标签剔除    removeExtraTag = re.compile('<.*?>')    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)        # strip()将前后多余内容删除        return x.strip()# 百度贴吧爬虫类class BDTB:    # 初始化，传入基地址，是否只看楼主的参数    def __init__(self, baseUrl, seeLZ, floorTag):        # base链接地址        self.baseURL = baseUrl        # 是否只看楼主        self.seeLZ = '?see_lz=' + str(seeLZ)        # HTML标签剔除工具类对象        self.tool = Tool()        # 全局file变量，文件写入操作对象        self.file = None        # 楼层标号，初始为1        self.floor = 1        # 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.defaultTitle = u"百度贴吧"        # 是否写入楼分隔符的标记        self.floorTag = floorTag    # 传入页码，获取该页帖子的代码    def getPage(self, pageNum):        try:            # 构建URL            url = self.baseURL + self.seeLZ + '&pn=' + str(pageNum)            request = urllib2.Request(url)            response = urllib2.urlopen(request)            # 返回UTF-8格式编码内容            return response.read().decode('utf-8')        # 无法连接，报错        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    # 获取帖子标题    def getTitle(self, page):        # 得到标题的正则表达式        pattern = re.compile('<h1 class="core_title_txt.*?>(.*?)</h1>', re.S)        result = re.search(pattern, page)        if result:            # 如果存在，则返回标题            return result.group(1).strip()        else:            return None    # 获取帖子一共有多少页    def getPageNum(self, page):        # 获取帖子页数的正则表达式        pattern = re.compile('<li class="l_reply_num.*?</span>.*?<span.*?>(.*?)</span>', re.S)        result = re.search(pattern, page)        if result:            return result.group(1).strip()        else:            return None    # 获取每一层楼的内容,传入页面内容    def getContent(self, page):        # 匹配所有楼层的内容        pattern = re.compile('<div id="post_content_.*?>(.*?)</div>', re.S)        items = re.findall(pattern, page)        contents = []        for item in items:            # 将文本进行去除标签处理，同时在前后加入换行符            content = "\n" + self.tool.replace(item) + "\n"            contents.append(content.encode('utf-8'))        return contents    def setFileTitle(self, title):        # 如果标题不是为None，即成功获取到标题        if title is not None:            self.file = open(title + ".txt", "w+")        else:            self.file = open(self.defaultTitle + ".txt", "w+")    def writeData(self, contents):        # 向文件写入每一楼的信息        for item in contents:            if self.floorTag == '1':                # 楼之间的分隔符                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)        # 出现写入异常        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()