你都怎樣看知乎日報？

1.分析知乎日報網頁（http://daily.zhihu.com/）

<span class="title">這樣一分析，你就明白該在哪裏投廣告了</span></a></div></div><div class="wrap"><div class="box"><a href="/story/9269183" class="link-button"><img src="http://pic2.zhimg.com/05c67496e38f662958a141847a734ffd.jpg" class="preview-image"><span class="title">有些熱鬧的「共享經濟」，恐怕只是一個美好的童話</span></a></div></div><div class="wrap"><div class="box"><a href="/story/9268452" class="link-button"><img src="http://pic3.zhimg.com/da8d8d3bf282170379c51ea0cf1ae4a6.jpg" class="preview-image"><span class="title">讓孩子擁有屬於本身的無聊時光，到底有多重要？</span></a></div></div><div class="wrap"><div class="box"><a href="/story/9269792" class="link-button"><img src="http://pic2.zhimg.com/245f3cf8dd4bfdd1bf0911ba4b486295.jpg" class="preview-image"><span class="title">看不懂，說人話，否則公司就虧大發了</span></a></div></div><div class="wrap"><div class="box"><a href="/story/9269818" class="link-button"><img src="http://pic3.zhimg.com/8b1588e23187bb05d160d599bbfe1752.jpg" class="preview-image"><span class="title">《金剛狼 3》中有哪些隱藏的彩蛋和有趣的細節？</span></a></div></div><div class="wrap"><div class="box"><a href="/story/9266807" class="link-button"><img src="http://pic1.zhimg.com/4cb4d5dec4a68553e41dcbd483010e84.jpg" class="preview-image"><span class="title">瞎扯 · 如何正確地吐槽</span></a></div></div><div class="wrap"><div class="box"><a href="/story/9259222" class="link-button"><img src="http://pic4.zhimg.com/16378a8129349aface9694cd27c71e2f.jpg" class="preview-image"><span class="title">小事 · 愛無能</span></a></div></div><div class="wrap"><div class="box"><a href="/story/9267167" class="link-button"><img src="http://pic1.zhimg.com/fdf5e0ff47de69d615f706559a260168.jpg" class="preview-image">

每個話題和圖片都在一個span標籤裏

<span class="title">這樣一分析，你就明白該在哪裏投廣告了</span></a></div></div><div class="wrap"><div class="box"><a href="/story/9269183" class="link-button"><img src="http://pic2.zhimg.com/05c67496e38f662958a141847a734ffd.jpg" class="preview-image">

很簡單構造一個正則表達式去匹配上面（獲取標題，圖片，連接）

pattern=re.compile(u'<span class="title">(.*?)</span>.*?'+
        u'<a href="(.*?)".*?'+
        u'<img src="(.*?)".*?'
        ,re.S)

2.下載頁面匹配正則表達式

先建立一個請求頭

self.header={
            'Accept':'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
            'Accept-Encoding':'gzip, deflate, sdch',
            'Accept-Language':'zh-CN,zh;q=0.8',
            'Cache-Control':'max-age=0',
            'Connection':'keep-alive',
            'Host':'daily.zhihu.com',
            'Referer':'https://www.baidu.com/link?url=Eh6CKs72Buyf0LEjPd1795QSL8ZK74kwItBvzaybausT6proAZIr3UkkmMPSDfk7&wd=&eqid=d1bd8fd9004118c90000000258bd8149',
            'Upgrade-Insecure-Requests':'1',
            'User-Agent':'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/56.0.2924.76 Chrome/56.0.2924.76 Safari/537.36'
        }

使用下載頁面使用正則匹配

html=self.req.get(url=self.url,headers=self.header)
        pattern=re.compile(u'<span class="title">(.*?)</span>.*?'+
        u'<a href="(.*?)".*?'+
        u'<img src="(.*?)".*?'
        ,re.S)
        T=list()
        self.l=re.findall(pattern,html.text)

3.使用多線程下載圖片

T=list()
        self.l=re.findall(pattern,html.text)
        for i in self.l:
            self.w.write(str(i)+'\n')
            #if(self.n<29):
            t=Thread(target=self.getimg,args=(i[2],self.n))
                #self.getimg(i[2],self.n)
            T.append(t)
            t.start()
            #print(i)
            self.n+=1
            #time.sleep(1)
        for tt in T:
            tt.join()

def getimg(self,src,n):
        try:
            h=self.req.get(url=src)
            s=open(str(n)+'.jpg','wb')
            s.write(h.content)
            s.close()
        except requests.exceptions.MissingSchema:
            print('這個url無效',n)

4.結果

所有代碼：

#!/usr/bin/python3
#coding:utf8
import requests
import re
import time
from threading import Thread
class main(object):
    def __init__(self):
        self.url='http://daily.zhihu.com/'
        self.l=list()
        self.n=0
        self.req=requests.Session()
        self.header={
            'Accept':'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
            'Accept-Encoding':'gzip, deflate, sdch',
            'Accept-Language':'zh-CN,zh;q=0.8',
            'Cache-Control':'max-age=0',
            'Connection':'keep-alive',
            'Host':'daily.zhihu.com',
            'Referer':'https://www.baidu.com/link?url=Eh6CKs72Buyf0LEjPd1795QSL8ZK74kwItBvzaybausT6proAZIr3UkkmMPSDfk7&wd=&eqid=d1bd8fd9004118c90000000258bd8149',
            'Upgrade-Insecure-Requests':'1',
            'User-Agent':'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/56.0.2924.76 Chrome/56.0.2924.76 Safari/537.36'
        }
    def getpage(self):
        html=self.req.get(url=self.url,headers=self.header)
        pattern=re.compile(u'<span class="title">(.*?)</span>.*?'+
        u'<a href="(.*?)".*?'+
        u'<img src="(.*?)".*?'
        ,re.S)
        T=list()
        self.l=re.findall(pattern,html.text)
        for i in self.l:
            self.w.write(str(i)+'\n')
            #if(self.n<29):
            t=Thread(target=self.getimg,args=(i[2],self.n))
                #self.getimg(i[2],self.n)
            T.append(t)
            t.start()
            #print(i)
            self.n+=1
            #time.sleep(1)
        for tt in T:
            tt.join()
    def getimg(self,src,n):
        try:
            h=self.req.get(url=src)
            s=open(str(n)+'.jpg','wb')
            s.write(h.content)
            s.close()
        except requests.exceptions.MissingSchema:
            print('這個url無效',n)


if __name__=='__main__':
    p=main()
    p.w=open('zh.txt','w')
    p.getpage()
    p.w.close()

項目地址：https://git.oschina.net/nanxun/zhihuribao