【python】抄写大神的百度贴吧代码

原文链接:http://cuiqingcai.com/993.html

划重点:

  1.提取帖子内容时,对图片,贴吧自动增加的超链接,制表符,换行符要做删除或替换处理

  2.decode是把bytes转换为str, encode是把str转换为bytes  原帖中的代码第100行多了一个encode,导致出错

  3.代码中用到了文件相关操作

  4.原文中获取标题的正则表达式我觉得不太对,做了修改。原文只是提取了<h1></h1>直接的,但实际上有在<h3></h3>直接的

最终代码如下,在python3.4.3中实现

import urllib.request
import urllib.parse
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

    replaceLine = re.compile('<tr>|<div>|</div>|</p>')
    #将表格制表<td>替换为	
    replaceTD = re.compile('<td>')
    #把段落开头换为
加空两格
    replacePara = re.compile('<p.*?>')
    #将换行符或双换行符替换为

    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, "
", x)
        x = re.sub(self.replaceTD, "	", x)
        x = re.sub(self.replacePara, "
    ", x)
        x = re.sub(self.replaceBR, "
", x)
        x = re.sub(self.removeExtraTag, "", x)
        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):
        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"
        self.floorTag = floorTag
    #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 = urllib.request.Request(url)
            response = urllib.request.urlopen(request)
            return response.read().decode('utf-8','ignore') #注意转换成字符串
        except urllib.error.URLError as 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):
        pageCode = self.getPage(1)
        pattern = re.compile('''<hd class="core_title_txt.*?title="(.*?)" style=".*?</hd>''', re.S)
        result = re.search(pattern, pageCode)
        if result:
            title = result.group(1).strip() #这里注意,获取分组的方法
            return title
        else:
            return None
    
    #提取帖子页数
    def getPageNum(self):
        pageCode = self.getPage(1)
        pattern = re.compile('''<span class=.*?</span>.*?回复贴,共.*?<span class=.*?>(.*?)</span>''', re.S)
        result = re.search(pattern, pageCode)
        if result:
            pageNum = result.group(1).strip()
            return pageNum
        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)
        contents = []
        for item in items:
            content = "
"+self.tool.replace(item)+"
"
            contents.append(content)
        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):
        #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 = "
" + str(self.floor) + "楼-------------------------------------"
                self.file.write(floorLine)
            self.file.write(item)
            self.floor+=1
    
    def start(self):
        pageNum = self.getPageNum()
        title = self.getTitle()
        self.setFileTitle(title)
        if pageNum == None:
            print(u"URL已失效,请重试")
            return 
        try:
            print("该帖子共有" + str(pageNum) + "")
            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 as 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(input(u'http://tieba.baidu.com/p/'))
seeLZ = input("是否只看楼主发言,是输入1,否输入0
")
floorTag = input("是否写入楼层信息,是输入1,否输入0
")
bdtb = BDTB(baseURL, seeLZ, floorTag)
bdtb.start()
原文地址:https://www.cnblogs.com/dplearning/p/4856009.html