有一个网站，其中列出了我要下载的文件。为了简化此过程，我尝试编写一个脚本来为我做。（即使我可以同时选择多个选项，也可以单击“提交”仅下载第一个文件）

网页的URL，webpage / list.php，与表单中的操作不同。我不确定在此处发布实际网址的政策。

<form action="webpage/data.php" method="post">
  <table align="center">
    <tbody>
      <tr><td>
        <select name="data[]" size="8" multiple="multiple">
          <option value="downloadable_file1.tar">Downloadable file1</option>
          <option value="downloadable_file2.tar">Downloadable file2</option>
          <option value="downloadable_file3.tar">Downloadable file3</option>
        </select>
      </td></tr>
    </tbody>
  </table>
  <input type="submit">
</form>

我拥有的脚本是这样的：

import urllib
import urllib2
import shutil

req = urllib2.Request('webpage/list.php')
values = { 'data[]': 'downloadable_file1.tar'}
req.add_data(urllib.urlencode(values))
resp = urllib2.urlopen(req)

myfile = open('downloadable_file1.tar', 'wb')
shutil.copyfileobj(resp.fp, myfile)
myfile.close()

运行脚本时，服务器似乎没有确认请求，只是为我提供了与文件列表相同的网页。我有没有选择？可能会有som重定向问题？

这是我在使用Chrome时获得的信息：

Request URL:webpage/data.php  
Request Method:POST  
Status Code:200 OK

Accept:text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8  
Accept-Charset:ISO-8859-1,utf-8;q=0.7,*;q=0.3  
Accept-Encoding:gzip,deflate,sdch  
Accept-Language:sv-SE,sv;q=0.8,en-US;q=0.6,en;q=0.4  
Cache-Control:max-age=0  
Connection:keep-alive  
Content-Length:26  
Content-Type:application/x-www-form-urlencoded  
Host:webpage 
Origin:webpage  
Referer:webpage/list.php  
User-Agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/537.22 (KHTML, like Gecko) Chrome/25.0.1364.172 Safari/537.22  
data[]:downloadable_file1.tar

Accept-Ranges:bytes  
Cache-control:private  
Connection:Keep-Alive  
Content-Disposition:attachment; filename="downloadable_file1.tar.gz"  
Content-Length:1043436  
Content-Transfer-Encoding:binary  
Content-Type:application/x-gzip  
Date:Tue, 26 Mar 2013 20:18:58 GMT  
Expires:Mon, 26 Jul 1997 05:00:00 GMT  
Keep-Alive:timeout=5, max=100  
Pragma:private  
Server:Apache/2.2.9 (FreeBSD) mod_ssl/2.2.9 OpenSSL/0.9.7e-p1 DAV/2 PHP/5.2.6 with Suhosin-Patch
X-Powered-By:PHP/5.2.6