class HTTP10Connection(HTTPConnection):
    _http_vsn = 10
_http_vsn_str = 'HTTP/1.0'


class HTTP10Handler(HTTPHandler):

    def http_open(self, req):
        return self.do_open(HTTP10Connection, req)
opener = build_opener(HTTP10Handler)
print(opener.open('http://stackoverflow.com/q/13656757').read()[:100])
How to send HTTP/1.0 request via urllib2?