When I request a URL using urllib2, it appears that urllib2 always makes the request using HTTP 1.0, and not HTTP 1.1. I'm trying to use the "If-None-Match"/"ETag" HTTP headers to conserve bandwidth, but if I'm not mistaken, these are HTTP 1.1 headers, so I can't reasonably expect a web server to respond correctly to my requests. (In my limited testing, it looks like some servers respond correctly with an HTTP 304 status, while some respond with an HTTP 200 and a full response body.)
My specific issue notwithstanding, is there any way to force HTTP 1.1 to be used? Or am I doing something wrong? I've condensed my code into the following example, which produces similar results on two different setups, Python 2.3.2 on Windows and Python 2.2.1 on Debian Linux. With this particular URL, the server responds to my HTTP 1.0 request with an HTTP 1.1 response and an HTTP 304 status code, which suits my purposes, but I'd feel more comfortable if my outgoing response also declared itself to be an HTTP 1.1 request. Example code: import httplib httplib.HTTPConnection.debuglevel = 1 import urllib2 url = 'http://www.mozilla.org/images/firefox-oneoh-top.png' etag = '"788054-2d18-3b21a80"' request = urllib2.Request(url) request.add_header('If-None-Match', etag) opener = urllib2.build_opener() response = opener.open(request) Example output: connect: (www.mozilla.org, 80) send: 'GET /images/firefox-oneoh-top.png HTTP/1.0\r\nHost: www.mozilla.org\r\nUser-agent: Python-urllib/2.0a1\r\nIf-none-match: "788054-2d18-3b21a80"\r\n\r\n' reply: 'HTTP/1.1 304 Not Modified\r\n' header: Date: Tue, 21 Dec 2004 21:56:27 GMT header: Server: Apache/2.0.46 (Red Hat) header: Connection: close header: ETag: "788054-2d18-3b21a80" Traceback (most recent call last): File "urllib2-test.py", line 11, in ? response = opener.open(request) File "D:\Python\lib\urllib2.py", line 333, in open '_open', req) File "D:\Python\lib\urllib2.py", line 313, in _call_chain result = func(*args) File "D:\Python\lib\urllib2.py", line 849, in http_open return self.do_open(httplib.HTTP, req) File "D:\Python\lib\urllib2.py", line 843, in do_open return self.parent.error('http', req, fp, code, msg, hdrs) File "D:\Python\lib\urllib2.py", line 359, in error return self._call_chain(*args) File "D:\Python\lib\urllib2.py", line 313, in _call_chain result = func(*args) File "D:\Python\lib\urllib2.py", line 419, in http_error_default raise HTTPError(req.get_full_url(), code, msg, hdrs, fp) urllib2.HTTPError: HTTP Error 304: Not Modified -- http://mail.python.org/mailman/listinfo/python-list
