[gentoo-user] Why exactly am I supposed to install Python 3?

[gentoo-user] Why exactly am I supposed to install Python 3?

[Grant Edwards]

My most recent update displayed the following messages from
Python 2.6.4 and Python 2.4.6:

  "It is highly recommended to additionally install Python 3,"

Why is it highly recommended?  I use a lot of modules that
aren't support by Python 3, and AFAICT few of the system
applications will even work with Python 3.  So why is
installing it "highly recommended"?
  
-- 
Grant Edwards                   grante             Yow! I'm having fun
                                  at               HITCHHIKING to CINCINNATI
                               visi.com            or FAR ROCKAWAY!!

Re: [gentoo-user] Why exactly am I supposed to install Python 3?

[Alan McKinnon]

On Monday 07 December 2009 22:24:14 Grant Edwards wrote:
> My most recent update displayed the following messages from
> Python 2.6.4 and Python 2.4.6:
> 
>   "It is highly recommended to additionally install Python 3,"
> 
> Why is it highly recommended?  I use a lot of modules that
> aren't support by Python 3, and AFAICT few of the system
> applications will even work with Python 3.  So why is
> installing it "highly recommended"?

Because that's the python ebuild maintainer's opinion. 
Python-3 is new! shiny! and he likely thinks it's cool.

There is no good reason to follow this advice just yet, as you rightly note 
very little (if anything) *requires* python-3 at this juncture.

The only benefit, which is questionable, is that python-3 is where its at 
development-wise, and maybe perhaps the 2* series will become unmaintained 
(shades of KDE-3). But I suspect that day is still far off.

-- 
alan dot mckinnon at gmail dot com

Re: [gentoo-user] Why exactly am I supposed to install Python 3?

[Neil Bothwick]

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On Mon, 7 Dec 2009 23:10:18 +0200, Alan McKinnon wrote:

> The only benefit, which is questionable, is that python-3 is where its
> at development-wise, and maybe perhaps the 2* series will become
> unmaintained (shades of KDE-3). But I suspect that day is still far off.

Also, as things are able to make use of Python 3, it will be there. But
that doesn't warrant a "highly recommended", if anything needs it,
portage will install it anyway.


-- 
Neil Bothwick

Crime doesn't pay? Does that mean my job is illegal?

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[gentoo-user] Re: Why exactly am I supposed to install Python 3?

[Grant Edwards]

On 2009-12-07, Alan McKinnon <alan.mckinnon@gmail.com> wrote:
> On Monday 07 December 2009 22:24:14 Grant Edwards wrote:
>> My most recent update displayed the following messages from
>> Python 2.6.4 and Python 2.4.6:
>> 
>>   "It is highly recommended to additionally install Python 3,"
>> 
>> Why is it highly recommended?  I use a lot of modules that
>> aren't support by Python 3, and AFAICT few of the system
>> applications will even work with Python 3.  So why is
>> installing it "highly recommended"?
>
> Because that's the python ebuild maintainer's opinion. 
> Python-3 is new! shiny! and he likely thinks it's cool.

Here's the entire message:

  It is highly recommended to additionally install Python 3,
  but without configuring Python wrapper to use Python 3.

After puzzling over it for while, I think maybe it's supposed
to mean:

  If you want to install/use Python 3 it is highly recommended
  that you do not configure Python wrapper to use Python 3.

> There is no good reason to follow this advice just yet, as you
> rightly note very little (if anything) *requires* python-3 at
> this juncture.
>
> The only benefit, which is questionable, is that python-3 is
> where its at development-wise, and maybe perhaps the 2* series
> will become unmaintained (shades of KDE-3). But I suspect that
> day is still far off.

That's _years_ away.  The 2.x series is still being actively
developed and maintained.  AFAICT, there are still a lot of
modules and programs that don't work with Python 3.  I wouldn't
expect people working on "production" code to move away from
2.x for a long time.

Quoting from the page on Python 2.7 (released today):

  Python 2.7 is scheduled to be the last major version in the
  2.x series before it moves into 5 years of bugfix-only mode.

So there's at least 5 years of life left in the 2.x series.  

-- 
Grant Edwards                   grante             Yow! I am covered with
                                  at               pure vegetable oil and I am
                               visi.com            writing a best seller!

Re: [gentoo-user] Re: Why exactly am I supposed to install Python 3?

[Alan McKinnon]

On Tuesday 08 December 2009 00:41:57 Grant Edwards wrote:
> Quoting from the page on Python 2.7 (released today):
> 
>   Python 2.7 is scheduled to be the last major version in the
>   2.x series before it moves into 5 years of bugfix-only mode.
> 
> So there's at least 5 years of life left in the 2.x series.  
> 

Agreed. The elog message strikes me as merely an enthusiastic endorsement of 
cool shiny new stuff from an over-zealous maintainer who doesn't quite grasp 
how slow traction can be in the real world

-- 
alan dot mckinnon at gmail dot com

[gentoo-user] Re: Why exactly am I supposed to install Python 3?

[Remy Blank]

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Alan McKinnon wrote:
> Agreed. The elog message strikes me as merely an enthusiastic endorsement of 
> cool shiny new stuff from an over-zealous maintainer who doesn't quite grasp 
> how slow traction can be in the real world

While that may be true, and even though he did make a few mistakes in
the beginning, arfrever has been doing a tremendous job getting Python
"back on track". In particular, he added the possibility to have Python
packages install their modules into multiple Python slots, a much needed
feature that makes testing software with multiple Python versions much
easier.

So, going back to the initial question, you could just emerge Python
3.1, enable it in USE_PYTHON in make.conf, but leave 2.6 as a default.
From this point, all packages that support 3.1 will be installed for 3.1
as well, and the day you want to switch, you'll just be able to enable
it and very few packages will need to be rebuilt. I have 2.4, 2.5, 2.6
and 3.1 in my USE_PYTHON, with 2.6 as default, and it's been working
great for a few months now.

Or you could just ignore the message. It probably won't make a
difference if you don't need multiple Python versions.

-- Remy


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Re: [gentoo-user] Re: Why exactly am I supposed to install Python 3?

[Neil Bothwick]

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On Tue, 08 Dec 2009 09:02:47 +0100, Remy Blank wrote:

> So, going back to the initial question, you could just emerge Python
> 3.1, enable it in USE_PYTHON in make.conf, but leave 2.6 as a default.

Where is USE_PYTHON documented? I see no mention of it in man make.conf,
make.conf.example or the portage elogs. 


-- 
Neil Bothwick

I'm Marvin of Borg. Guess what kinds of weapons we have. Go on, guess.

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[gentoo-user] Re: Why exactly am I supposed to install Python 3?

[Remy Blank]

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Neil Bothwick wrote:
> Where is USE_PYTHON documented? I see no mention of it in man make.conf,
> make.conf.example or the portage elogs. 

In /usr/portage/eclass/python.eclass ;-)

To be honest, I wanted that feature so badly that I dug through
python.eclass as soon as I saw arfrever mention it. From the code, it
seemed to make sense that USE_PYTHON should be added to make.conf, and
indeed it works. But I may have misunderstood completely and the
"feature" could be removed or modified at any time.

So it's probably a good idea to stay away from it until it has been
documented properly.

-- Remy


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Re: [gentoo-user] Why exactly am I supposed to install Python 3?

[Peter Humphrey]

On Monday 07 December 2009 22:14:55 Neil Bothwick wrote:
> On Mon, 7 Dec 2009 23:10:18 +0200, Alan McKinnon wrote:
> > The only benefit, which is questionable, is that python-3 is where its
> > at development-wise, and maybe perhaps the 2* series will become
> > unmaintained (shades of KDE-3). But I suspect that day is still far off.
>
> Also, as things are able to make use of Python 3, it will be there. But
> that doesn't warrant a "highly recommended", if anything needs it,
> portage will install it anyway.

There's another wrinkle, too. I did follow the recommendation and install 
Python 3, but what will happen when my current 2.6.4 is upgraded to, say, 
2.7.0 and I want to run python-updater? Will I find myself updated to version 
3 instead?

Maybe I should just remove Python 3 pro tem.

-- 
Rgds
Peter

Re: [gentoo-user] Why exactly am I supposed to install Python 3?

[Dale]

Peter Humphrey wrote:
> On Monday 07 December 2009 22:14:55 Neil Bothwick wrote:
>   
>> On Mon, 7 Dec 2009 23:10:18 +0200, Alan McKinnon wrote:
>>     
>>> The only benefit, which is questionable, is that python-3 is where its
>>> at development-wise, and maybe perhaps the 2* series will become
>>> unmaintained (shades of KDE-3). But I suspect that day is still far off.
>>>       
>> Also, as things are able to make use of Python 3, it will be there. But
>> that doesn't warrant a "highly recommended", if anything needs it,
>> portage will install it anyway.
>>     
>
> There's another wrinkle, too. I did follow the recommendation and install 
> Python 3, but what will happen when my current 2.6.4 is upgraded to, say, 
> 2.7.0 and I want to run python-updater? Will I find myself updated to version 
> 3 instead?
>
> Maybe I should just remove Python 3 pro tem.
>   

I think this is correct.  Use eselect to set it to the new python, 2.7 
or whatever, then run python updater.  I seem to recall doing mine that 
way before.

Also, I think you can specify what version you want to upgrade/downgrade 
to as well.  python-updater <version number> or something to that effect.

When I installed python 3 a while back, portage wouldn't select it 
automatically since it would break things.  I guess that is handy for 
the time being.

Dale

:-)  :-)