[Python-Dev] RELEASED Python 3.0 final

[glyph at divmod.com]

As far as the original point of this thread, I started off just 
defending the cautionary text already present in the announcements and 
on the website.  Since I'm not advocating any changes to that (the brief 
caveat on the "download" page is fine), we'll just have to agree to 
disagree on the abstractly appropriate audience for 3.0.  I'll respond 
to some other points though:

On 05:54 pm, guido at python.org wrote:
>On Fri, Dec 5, 2008 at 9:28 PM,  <glyph at divmod.com> wrote:
>>On 5 Dec, 06:10 pm, guido at python.org wrote:
>>>On Thu, Dec 4, 2008 at 11:27 PM,  <glyph at divmod.com> wrote:

>I think it's great to have specific marketing targeted towards library
>developers. I know we haven't done enough -- for example I promised a
>C extension porting guide which didn't materialize. :-(

Well, get cracking, then! :)
>If you can't find it in your heart to recommend
>3.0, can you at least keep that within your circle of
>library-producing friends?

In another (longer) message, I already said this is what I'm doing. 
Assuming that we are all my "library-producing friends" here :).  I am 
deliberately refraining from blogging about 3.0 until I have something 
nice to say.

But still, you can't honestly expect me to recommend 3.0 until someone 
has gotten at least a basic skeleton of Twisted up and running under it 
:).  My own attempts to do so have failed miserably, to the point where 
I can't even produce a useful bug report without a lot more work.

Would you recommend a C compiler that couldn't build Python, or link 
with it?
>Whenever someone asks me which version to use, I alwasys respond with
>a question -- what do you want to use it for?

In the longer term, I think that you should look at this as a symptom of 
a problem.  If you learn Java, you learn the most recent version.  If 
you need your software to work with an older version, you just pass a 
special option to the compiler.  If you want your *old* software to work 
with a *new* version, it basically just does (at least, 99% of the 
time).

I don't think there's anything about the 3.0 language which couldn't be 
supported in a VM that understood both 2 and 3.  "py3to2" seems at least 
a rough proof of concept of that idea, although it still has some 
issues.  Library availability should be a separate concern from a clean 
source language.

I also don't think 3.0 is perfect, and five years on, there will be a 
temptation to make more "just this once" incompatible changes.  Of 
course, you've promised these changes won't be made, and *this* set of 
design mistakes will be with us forever.  It would be nice if there were 
a way for evolution to continue without another reboot of the world.
>If they're that easily convinced that Java is better they probably
>were a lost cause anyway, so I won't mourn their departure too much.

I really believe that *all* new users are fickle, if they don't have a 
mandate as to what they need to be learning.  Personally, I learned 
Python because of a memory leak in Swing.