python学习笔记（10）--爬虫下载煎蛋图片

说明：

1. 有很多细节需要注意！

2. str是保留字，不要作为变量名

3. 保存为txt报错，encoding=utf-8

4. 403错误，添加headers的方法

5. 正则match只能从开头匹配，search可以中间匹配，返回对象，可以用span()查看匹配的字符索引，不过还是用findall全部查找比较方便，直接返回一个数组。

 1 import urllib.request
 2 import re
 3 
 4 # <span class="current-comment-page">[1292]</span>
 5 # <img src="//ww2.sinaimg.cn/mw600/7064b124jw1enncg4zsmij20dw0ijgn0.jpg" style="max- 480px; max-height: 750px;">
 6 # url = "http://placekitten.com/300/300"
 7 # url = "http://placehold.it/300/300"
 8 # url = "http://www.tuwenclub.com"
 9 
10 url = "http://jandan.net/ooxx"
11 response = urllib.request.urlopen(url)
12 html = response.read().decode("utf-8")
13 
14 # html = response.read().decode("utf-8")
15 # html = response.read().decode("gbk")
16 # 
17 # print(html[0:1000])
18 # page = html.find("current-comment-page")
19 # pageNum = html[page+23:page+27]
20 # imglist = []
21 reImg = r"//[0-9a-z]+.sinaimg.cn.+?.jpg"
22 strs = "//ww2.sinaimg.cn/mw600/7064b124jw1enncg4zsmij20dw0ijgn0.jpg"
23 
24 imgs = re.findall(reImg, html)
25 headers = {'User-Agent':'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:23.0) Gecko/20100101 Firefox/23.0'}  
26 # print(img1)
27 for i in range(0,10):
28     urlImg = "http:" + imgs[i]
29     req = urllib.request.Request(url=urlImg, headers=headers)  
30     response = urllib.request.urlopen(req)
31     img = open(str(i)+".jpg","wb")
32     img.write(response.read())
33     img.close()