python 爬虫第二例--百度贴吧

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

class Tool:
    # 去除Img标签
    removeImg = re.compile(r‘<img.*?>| {0,100}|‘)
    # 删除超链接标签
    removeAddr = re.compile(r‘<a.*?>|</a>‘)
    # 把换行标签转换为\n
    replaceLine= re.compile(r‘<tr>|<div>|</div>|</p>‘)
    # 把表格制表转换为\t
    replaceTD = re.compile(r‘<td>‘)
    # 把段落开头转换为\n加两个空格
    replacePara = re.compile(‘<br><br>|<br>|<br><br><br>‘)
    # 将其余标签去除
    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.removeExtraTag, "", x)
        # 使用strip() 方法将前后多余内容删除
        return x.strip()
class BDTB:
    #初始化变量，传入基类地址，传入是否只看楼主参数
    def __init__(self, baseUrl, onlyLz, floorTag):
        # 基地址
        self.baseUrl = baseUrl
        # 是否只看楼主
        self.onlyLz = ‘?see_lz=‘ + str(onlyLz)
        # 实例化替换去除标签类
        self.tool = Tool()
        # 全局file变量，文件写入操作对象
        self.file = None
        # 默认标签，若没有获得标题，使用此标题
        self.defaultTitle = u"百度贴吧帖子"
        # 是否写入楼层信息
        self.floorTag = floorTag
    # 传入页码，获取该帖子的代码
    def getPage(self, pageNum):
        try:
            url = self.baseUrl + self.onlyLz + ‘&pn=‘ + str(pageNum)
            request = urllib2.Request(url)
            response = urllib2.urlopen(request)
            return response.read().decode(‘utf-8‘)
        except urllib2.URLError,e:
            if hasattr(e, ‘code‘):
                print u"连接百度贴吧失败,错误编码:" + e.code
                return None
            if hasattr(e, ‘reason‘):
                print u"连接百度贴吧失败，错误原因:" + e.reason
                return None

    # 获取帖子的标题
    def getTitle(self, page):
        pattren = re.compile(r‘<h3 class="core_title_txt pull-left text-overflow  ".*?>(.*?)</h3>‘,re.S)
        items = re.search(pattren, page)
        if items:
            # print items.group(1).strip()
            return items.group(1).strip()
        else:
            return None

    # 提取帖子页数
    def getPageNum(self, page):
        pattren = re.compile(r‘<ul class="l_posts_num">.*?<span class="red">(.*?)</span>‘,re.S)
        items = re.search(pattren, page)
        if items:
            # print items.group(1)
            return items.group(1).strip()
        else:
            return None
    # 提取正文内容
    def getContent(self, page):
        pattren = re.compile(r‘<div id="post_content_.*?>(.*?)</div>.*?<div class="core_reply_tail clearfix">.*?<span class="tail-info">(.*?)</span>.*?<span class="tail-info">(.*?)</span>‘,re.S)
        items = re.findall(pattren, page)
        contents = []
        for item in items:
            content = []
            title = "\n" + self.tool.replace(item[0]) + "\n"
            floor = item[1]
            writeTime = item[2]
            content.append(title.encode("utf-8"))
            content.append(floor.encode("utf-8"))
            content.append(writeTime.encode("utf-8"))
            contents.append(content)
        return contents
    # 设置文件名字
    def setFileTIltle(self, title):
        if title is not None:
            self.file = open(title + ".txt", "w+")
        else:
            self.file = open(self.defaultTitle + ".txt", "w+")
    # 将内容写入文件
    def writeData(self, contents):
        for item in contents:
            if self.floorTag == ‘1‘:
                floorLineTime = "\n" + item[1] +"-----------------------------\n"+item[2]
                self.file.write(floorLineTime)
            self.file.write(item[0])
            # floorLine = "\n" + item[‘‘]
            # print "------------------%s--------------------%s-----------------"%(item[1],item[2])
            # print self.tool.replace(item[0])
        # print self.tool.replace(items[1])
        # print items[1]
    def start(self):
        indexPage = self.getPage(1)
        pageNum = self.getPageNum(indexPage)
        title = self.getTitle(indexPage)
        self.setFileTIltle(title)
        if pageNum == None:
            print "URL已经失效"
        try:
            print "该帖子一共有"+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("是否只获取楼主的帖子是输入1，否输入0\n")
floorTag = raw_input("是否写入楼层与时间信息是输入1，否输入0\n")
bdtb = BDTB(baseUrl, seeLZ, floorTag)
bdtb.start()