[Python-Dev] Lib/http/client.py: could it return an OSError with the current response?

[Martin Panter]

On 30 August 2016 at 13:41, Ivo Bellin Salarin
<ivo.bellinsalarin at gmail.com> wrote:
> While using requests to tunnel a request via a proxy requiring user
> authentication, I have seen that httplib
> (https://hg.python.org/cpython/file/3.5/Lib/http/client.py#l831) raises the
> message returned by the proxy, along with its status code (407) without
> including the proxy response. This one could be very interesting to the
> consumer, since it could contain some useful headers (like the supported
> authentication schemes).

Here are some existing bug threads which may be relevant:

https://bugs.python.org/issue7291 (urllib.request support for handling
tunnel authentication)
https://bugs.python.org/issue24964 (get tunnel response header fields
in http.client)

> Would it be possible to change the http/client.py behavior in order to raise
> an exception including the whole response?

That would be one way, and might be good enough for getting a
Proxy-Authenticate value. Although there might be other ways that
also:

* Allow reading the body (e.g. HTML page) of the error response. IMO
an exception instance is the wrong place for this;
urllib.error.HTTPError is a bad example.
* Allow the tunnel response fields to be obtained even when the
request was successful

> If you don't see any problem with my proposal, how can I propose a pull
> request? :-)

Perhaps you can use one of the patches at one of the above bug reports
as a starting point. What you want seems to be a prerequisite for
Issue 7291 (urllib.request), so maybe we can discuss it there. Or open
a new bug to focus on the http.client-only aspect.