[Python-Dev] Patch making the current email package (mostly) support bytes

[R. David Murray]

On Fri, 08 Oct 2010 15:51:45 -0000, lutz at rmi.net wrote:
> For my part, one week from now I'll be standing up again in front 
> of a group of 20 Python beginners, and basically apologizing for 
> both the present and ongoing 3.X changes they must conform to in 
> the near future.  Python may not be Perl 6 yet, but its image is 
> already tarnished in the real world where people make technology 
> choices, due to its rapid pace of change.  It's a genuine problem.
> 
> In the end, I suppose I'm just one of those lazy end users you
> mentioned who are too busy to spend 24/7 hanging out on this 
> list in order to head off changes that will break their code. 
> (Yes, sarcasm intended.)

What would be helpful would be to know what changes it is that we
have made between 3.1 and 3.2 that are raising backward compatibility
concerns.  What are we doing that is perceived as "ongoing 3.X changes"?
Generalities will not help, only by looking at specifics can we
re-evaluate our actions.

In a private message you mentioned "the bytecode file model change", by
which I presume you mean PEP 3147.  Our view is that this is a backward
compatible change:  any Python program that was working should continue
to work.  Barry's original idea was that the new behavior would only be
turned on by a flag, but Guido (and others) wanted it to be the default
because in his view it is a superior arrangement for normal use.

Perhaps we did not fully consider the effect on third party tools (and,
as you point out, documentation) that expects .pyc files along side the
.py files.  Yet this change is no where near the level of change that
makes typical Python programs fail.  We feel like it is a worthwhile
trade-off (and Debian and Ubuntu at least may well backport it to earlier
Python versions).  But apparently you disagree.

So, engage us in dialog about it, please.  And *please* mention any
other specific changes you think are disruptive between 3.1 and 3.2.
We need to know about them, preferably *before* we release 3.2 beta
(currently targeted for the end of this month).  Because I assure you
that it is not our policy to be changing things any more rapidly than
we did between python 2.x versions[*].

If you feel like you are apologizing to your groups of beginners,
it would be wonderful if you could act as their advocate here.
Obviously the issues directly affect you, so hopefully it is worth
your time to engage us on this topic.

And thank you for the messages you have sent.  I know they have made
me even more careful than I was already trying to be.

--
R. David Murray                                      www.bitdance.com

[*] There may be a few exceptions to this where the 3.x library code
fails to work in real-world applications, so that a more radical change
is made but is, in reality, a bug fix.  But even there we try to be
conservative.