最近研究python爬虫,按照网上资料实现了python爬虫爬取糗事百科,做个笔记。
    
   
    
     分享几个学习python爬虫资料:
    
   
    
     
      廖雪峰python教程
     
     主要讲解python的基础编程知识
    
   
    
     python开发简单爬虫
    
    
     通过一个实例讲解python爬虫的整体结构
    
   
    
     
      python正则表达式
     
     讲解爬虫中匹配中所需要的正则表达式
    
   
    
     
      python爬虫系列教程
     
     几个训练的实例
    
   
    
     简单爬虫的架构
    
   
    
     
     
    
   
    
     爬虫的运行流程
    
   
    
    
   
    
     下面按照教程中的讲解实现python爬虫爬取糗事百科
    
   
    
     新建工程
    
   
    
     
     
    
   
    
     新建pydev package
    
   
    
     
     
    
   
    
     新建pydev module
    
   
    
     
    
   
    
     编辑代码:
    
   
import urllib2
import re
class QSBK:
 
 
    def __init__(self):
        self.pageIndex =2
        self.user_agent = 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'
        self.headers = { 'User-Agent' : self.user_agent } 
        self.stories = []
        self.enable = False
   
    def getPage(self,pageIndex):
        try:
            url = ' http://www.qiushibaike.com/hot/page/' + str(pageIndex)
            request = urllib2.Request(url,headers = self.headers)
            response = urllib2.urlopen(request)
            pageCode = response.read().decode('utf-8')
            return pageCode
 
        except urllib2.URLError, e:
            if hasattr(e,"reason"):
                print u"连接糗事百科失败,错误原因",e.reason
                return None
 
 
 
    def getPageItems(self,pageIndex):
        pageCode = self.getPage(pageIndex)
        if not pageCode:
            print "页面加载失败...."
            return None
        
        pattern = re.compile(r'<div.*?class="author.*?>.*?<a.*?</a>.*?<a.*?>(.*?)</a>.*?<div.*?class'+
                     '="content".*?>(.*?)</div>(.*?)<div class="stats.*?class="number">(.*?)</i>',re.S)
        items = re.findall(pattern,pageCode)
        pageStories = []
        for item in items:
            replaceBR = re.compile('<br/>')
            text = re.sub(replaceBR,"\n",item[1])
            pageStories.append([item[0].strip(),text.strip(),item[2].strip(),item[3].strip()])
        return pageStories
 
    def loadPage(self):
        if self.enable == True:
            if len(self.stories) < 2:
                pageStories = self.getPageItems(self.pageIndex)
                if pageStories:
                    self.stories.append(pageStories)
                    self.pageIndex += 1
    
    def getOneStory(self,pageStories,page):
        for story in pageStories:
            input = raw_input()
            self.loadPage()
            if input == "Q":
                self.enable = False
                return
            print u"第%d页\t发布人:%s\t赞:%s\n%s" %(page,story[0],story[3],story[1])
    
    def start(self):
        print u"正在读取糗事百科,按回车查看新段子,Q退出"
        self.enable = True
        self.loadPage()
        nowPage = 0
        while self.enable:
            if len(self.stories)>0:
                pageStories = self.stories[0]
                nowPage += 1
                del self.stories[0]
                self.getOneStory(pageStories,nowPage)
 
 
spider = QSBK()
spider.start()
    
     运行结果:
    
   
    
   
    
     对于不同的网页,请右键“审查元素”查看网页代码,修改一下正则表达式
    
   
 
