用Python从网站爬图片

从极客学院首页爬几张图片：

一下为titita.txt内容，为极客学院首页源代码节选：

<div class="jk-uptodate">
    <h2>最新课程</h2>
    <ul>
        
        <li class="uptodate">
            <a href="/zhiye/course/135.html?type=50" target="_blank">
                <img class="uptodate-img" src="https://jiuye-res.jikexueyuan.com/zhiye/showcase/attach-/20170928/8cc3edeb-0115-43ea-a46f-db6c6e9255ca.jpg" alt="">
                <p class="uptodate-title">Keras框架入门实战</p>
                <p class="uptodate-info">
                    初级
                    <span>|</span>5门课
                    
                </p>
            </a>
        </li>
        
        <li class="uptodate">
            <a href="/zhiye/course/143.html?type=38" target="_blank">
                <img class="uptodate-img" src="https://jiuye-res.jikexueyuan.com/zhiye/showcase/attach-/20171101/b12ae422-fd63-4b7d-a0d3-13c3ab4479c5.jpg" alt="">
                <p class="uptodate-title">【实战】Python与消息中间件</p>
                <p class="uptodate-info">
                    中级
                    <span>|</span>4门课
                    
                </p>
            </a>
        </li>
        
        <li class="uptodate">
            <a href="/zhiye/course/134.html?type=50" target="_blank">
                <img class="uptodate-img" src="https://jiuye-res.jikexueyuan.com/zhiye/showcase/attach-/20170928/85a3364e-47a3-41df-b5c8-daf48a57b7cd.jpg" alt="">
                <p class="uptodate-title">深入浅出 — 自然语言处理</p>
                <p class="uptodate-info">
                    初级
                    <span>|</span>8门课
                    
                </p>
            </a>
        </li>
        
        <li class="uptodate">
            <a href="/zhiye/course/145.html?type=18" target="_blank">
                <img class="uptodate-img" src="https://jiuye-res.jikexueyuan.com/zhiye/showcase/attach-/20171123/9625ede8-31e9-4edc-93e7-74bf5b752585.jpg" alt="">
                <p class="uptodate-title">Android性能优化－UI篇</p>
                <p class="uptodate-info">
                    中级
                    <span>|</span>7门课
                    
                </p>
            </a>
        </li>
        
    </ul>
</div>

爬图片的Python程序如下：

import re
import requests

f=open('titita.txt','r')
f1=f.read()
f.close()

htmls=re.findall('<img class="uptodate-img" src="(.*?)" alt="">',f1,re.S)
i=0
for each in htmls:
    print('nowdoloading:'+each)
    pic=requests.get(each)
    fp=open('pic\'+str(i)+'.jpg','wb')
    fp.write(pic.content)
    fp.close
    i+=1

#之前没安装requests，要新建项目

Pycharm输出为：

nowdoloading:https://jiuye-res.jikexueyuan.com/zhiye/showcase/attach-/20170928/8cc3edeb-0115-43ea-a46f-db6c6e9255ca.jpg
nowdoloading:https://jiuye-res.jikexueyuan.com/zhiye/showcase/attach-/20171101/b12ae422-fd63-4b7d-a0d3-13c3ab4479c5.jpg
nowdoloading:https://jiuye-res.jikexueyuan.com/zhiye/showcase/attach-/20170928/85a3364e-47a3-41df-b5c8-daf48a57b7cd.jpg
nowdoloading:https://jiuye-res.jikexueyuan.com/zhiye/showcase/attach-/20171123/9625ede8-31e9-4edc-93e7-74bf5b752585.jpg

爬到的图片在资源管理器中显示为：