# -*- coding:utf-8 -*-
import urllib
import urllib2
import 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):
		self.baseURL = baseUrl
		self.seeLZ = '?see_lz=' + str(seeLZ)
		self.tool = Tool()
		# 全局file变量，文件写入操作对象
		self.file = None
		# 楼层编号，初始为1
		self.floor = 1

	# 传入页码，获取该页帖子的代码
	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 "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 = self.getPage(1)
		pattern = re.compile('<h3 class="core_title_txt.*?>(.*?)</h3>', re.S)
		result = re.search(pattern, page)
		if result:
			# print result.group(1)  #测试输出
			return result.group(1).strip()
		else:
			return None

	# 获取帖子一共有多少页
	def getPageNum(self):
		page = self.getPage(1)
		pattern = re.compile('<li class="l_reply_num.*?</span>.*?<span.*?>(.*?)</span>', re.S)
		result = re.search(pattern, page)
		if result:
			# print result.group(1)  #测试输出
			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):
		pattern = re.compile('<div id="post_content_.*?>(.*?)</div>', re.S)
		items = re.findall(pattern, page)
		f = open('baidutb.txt', 'a')
		floor = 1
		for item in items:
			str1 = "\n%s楼------------------------------------------------------------------------------------------------------------------------------------\n"%floor
			str2 = self.tool.replace(item).encode('utf-8')
			str = str1 + str2
			floor += 1
			f.write(str)


baseURL = 'http://tieba.baidu.com/p/3138733512'
bdtb = BDTB(baseURL, 1)
bdtb.getContent(bdtb.getPage(1))