Open Stack

On 04/01/2014 04:40 AM, victor stinner wrote:
> Hi,
> 
> I will organize a sprint to Port OpenStack to Python 3 during 4 days
> at Montreal (Canada) during Pycon Montreal 2014, between April, 14
> (Monday) and April, 17 (Thursday).
> 
> The goal of the sprint is to port OpenStack components and OpenStack
> dependencies to Python 3,

This is a great goal, thank you! But I'm concerned it might be premature.

My concern is this. The singled biggest change in Py2 -> Py3 is string
handling, especially with regards to str vs. unicode. We have a
significant number of bugs in the current code base with regards to
encoding exceptions, I just got done fixing a number of them, I know
there are others. While I was fixing them I searched the OpenStack
coding guidelines to find out coding practices were supposed to be
enforcing with regards to non-ASCII strings and discovered there is
isn't much, it seems incomplete. Some of it seems based more on
speculation than actual knowledge of defined Python behavior. I'm not
sure, but given we do not have clear guidelines for unicode in Py2,
never mind guidelines that will allow running under both Py2 and Py3 I'm
willing to guess we have little in the gate testing that enforces any
string handling guidelines.

I'm just in the process of finishing up a document to address these
concerns. Unfortunately I'm going to be off-line for several weeks and I
didn't want to start a discussion I couldn't participate in (plus there
are some Py3 issues in the document I need to clean up) so I was going
to wait to post it.

My concern is we need to get our Py2 house in order *before* tackling
Py3 porting. Doing Py3 porting before we have clear guidelines on
unicode, str, bytes, encoding, etc. along with gate tests that enforce
these guidelines is putting the cart before the horse. Whatever patches
come out of a Py3 porting sprint might have to be completely redone.

FWIW projects that deal with web services, wire protocols, external
datastores, etc. who have already started porting to Py3 have
encountered significant pain points with Py3, some of which is just
being resolved and which have caused on-going changes in Py3. We deal
with a lot of these same issues in OpenStack. Before we just start
hacking away I think it would behoove us to first have a very clear and
explicit document on how we're going to address these issues *before* we
start changing code.



-- 
John