获取Urllib2.Request的请求头文件？

Question

有没有办法从使用Urllib2创建的请求中获取标题或确认使用urllib2.urlopen发送的HTTP标头？

Answer 1

一个简单的方法见请求（和响应标头）是使调试输出：

opener = urllib2.build_opener(urllib2.HTTPHandler(debuglevel=1)) 

然后，可以看到的精确头发送/收到：

>>> opener.open('http://python.org') 
send: 'GET/HTTP/1.1\r\nAccept-Encoding: identity\r\nHost: python.org\r\nConnection: close\r\nUser-Agent: Python-urllib/2.7\r\n\r\n' 
reply: 'HTTP/1.1 200 OK\r\n' 
header: Date: Tue, 14 Jun 2011 08:23:35 GMT 
header: Server: Apache/2.2.16 (Debian) 
header: Last-Modified: Mon, 13 Jun 2011 19:41:35 GMT 
header: ETag: "105800d-486d-4a59d1b6699c0" 
header: Accept-Ranges: bytes 
header: Content-Length: 18541 
header: Connection: close 
header: Content-Type: text/html 
header: X-Pad: avoid browser bug 
<addinfourl at 140175550177224 whose fp = <socket._fileobject object at 0x7f7d29c3d5d0>> 

还可以设置在提出请求之前使用urllib2.Request对象标题（并覆盖默认标题，尽管事先不在标题字典中）：

>>> req = urllib2.Request(url='http://python.org') 
>>> req.add_header('User-Agent', 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:5.0)') 
>>> req.headers 
{'User-agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:5.0)'}