Re: Python's carbon guilt

2020-10-11 Thread Michael Torrie
On 10/10/20 9:58 AM, Peter Pearson wrote:
> Python advocates might want to organize their thoughts on
> this subject before their bosses spring the suggestion:
> 
> From 
> https://www.sciencemag.org/news/2020/10/we-re-part-problem-astronomers-confront-their-role-and-vulnerability-climate-change
>  :
> 
> . . . Astronomers should also abandon popular programming languages
> such as Python in favor of efficient compiled languages. Languages
> such as Fortran and C++, Zwart calculates, are more than 100 times
> more carbon efficient than Python because they require fewer
> operations.

Most of the math heavy lifting is done by compiled code that is merely
called from Python.  I seriously doubt there is anything to save by
abandoning Python for something that is harder to use, slower, and
probably burns way more electricity with all those compile cycles that
they'd be forced to do.
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Re: Python's carbon guilt

2020-10-10 Thread Terry Reedy

On 10/10/2020 11:58 AM, Peter Pearson wrote:

Python advocates might want to organize their thoughts on
this subject before their bosses spring the suggestion:

 From 
https://www.sciencemag.org/news/2020/10/we-re-part-problem-astronomers-confront-their-role-and-vulnerability-climate-change
 :

 . . . Astronomers should also abandon popular programming languages
 such as Python in favor of efficient compiled languages. Languages
 such as Fortran and C++, Zwart calculates, are more than 100 times
 more carbon efficient than Python because they require fewer
 operations.


Here is my reply to the "senior correspondent for astronomy..." who 
wrote the columm.

---

Dear Mr. Clery:

You report that Zwart of Leiden U says ...

"Astronomers should also abandon popular programming languages such as 
Python in favor of efficient compiled languages. Languages such as 
Fortran and C++, Zwart calculates, are more than 100 times more carbon 
efficient than Python because they require fewer operations."


Summary counter claim: the claim is phony.  As actually used by 
astronomers for computationally intensive tasks, Python is nearly if not 
as 'carbon efficient' -- because nearly all the computation is done with 
machine code compiled from C, Fortran, C++, or whatever.


(I am not an expert here, but am reporting to you a summary of what is 
generally known among experienced Python users.  I am leaving out 
numerous details.  Feel free to contact scientific Python experts for more.)


Here is how anti-Python, pro-OtherLanguage people come up with such 
misleading numbers as '100x slower'.  Confuse the issue by ascribing 
efficiency to languages rather than implementations.  Then compare a 
relatively efficient 'production' implementation of some algorithm in 
OtherLanguage to an computer inefficient (but human efficient) 
'development' implementation in Python that ignores how Python is being 
used in practice by scientific communities, such as the astronomy community.


Step 1: Create a file with couple of numerically intensive functions 
such as matrix_init and matrix_invert written in directly compiled 
OtherLanguage.  Add calls to matrix_init and matrix_invert.  Time one or 
more runs.


Step 2: Naively translate OtherLanguage directly into Python.  Don't 
allow imports. Time one or more runs with the CPython interpreter. 
Compare the OtherLanguage time to this worst case Python time.  Imply 
that users of Python are stupid enough to stop here for production 
usage.  I consider this a bit slanderous.


In practice, Python users inverting matrices, for instance, import the 
compiled numpy module, which among other things, wraps the standard 
Linpack package, which  uses machine-specific, assemble-coded, Basic 
Linear Algebra Subroutines (BLAS) when available.  In practice, I have 
read, the overhead of calling C libraries from Python instead of C is 
only a few percent.


The original and still main Python implementation, CPython, is written 
in C.  It interprets Python code, which is 'slow', but the Python code 
can include calls to fast, compiled, pre-written C functions.  CPython 
was designed from the beginning to be extended with other other modules 
and functions written in C. (Fortran extensions were included either 
immediately or soon after, but I don't know which.)  Some of these are 
included in the standard library, others from third-parties.


Since the release of Python 1.0 in 1992, real-world Python users, have 
been extending CPython when appropriate for production usage.  Indeed, 
numerical scientific computation was Python's first 'killer 
application'.  Now, most every open-source C library with significant 
usage has been wrapped.  There are at least hundreds. The current 
standard numerical package, numpy, is the third, and the needs of 
astronomers were among those that contributed to the design.


--
Terry Jan Reedy

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Re: Python's carbon guilt

2020-10-10 Thread Tim Daneliuk
On 10/10/20 2:35 PM, Marco Sulla wrote:
> He should also calculate the carbon dioxide emitted by brains that
> works in C++ only. I omit other sources.
> 


yes, methane is an alleged greenhouse gas as well
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RE: Python's carbon guilt

2020-10-10 Thread Avi Gross via Python-list
People have a tendency to go too far in their religious zeal, Peter.

We could go back to writing on chalkboards to do calculations then re-use
the chalk dust when erasing to write again.

Many computers do almost nothing 90+ percent of the time. Want to outlaw
those or force them to accept random jobs from the internet when relatively
idle?

But all kidding aside, anything used frequently and not changed often might
be a good candidate for an efficient solution that uses fewer resources. Yet
our computers, so far, have been in many ways getting cheaper and in many
cases use less electricity to do the same number of calculations. But there
are tradeoffs such as optimizing speed over memory use or other resources
that are external and thus slower. 

The ultimate carbon cost can sometimes be for  carbon-based organisms, most
of them suitable to be called human. When you measure how long it takes them
to develop applications and verify they have minimal bugs, you may notice
that some development environments seem to take lots more time than others
for common tasks. Interactive has huge advantages in many cases. Slowest
would be asking people to go back to writing in machine code, not very
portably.

The reality is that speed and other resource use do matter for anything run
often or that would take a very long time. Languages like python and R
acknowledge that and quite a few parts are now replaced by calls to
libraries in other language or C/C++ code. But often that is done only later
when the code is not going to be changed regularly.

I think there is a reality here. The costs of computing end sometimes of
power usage, often are dropping. The users like getting extra features and
underneath the covers, that often means lots of extra IF statements or other
checks, or loops that keep checking regularly to see if they need to do
anything.  If you program a GUI that allows the user to click or type in
many places at random, there can be lots of overhead even when done in a
compiled language. True speed and efficiency might require removing lots of
features entirely as too expensive. It may well be cheaper to do some
operations on matrices where every row/column is of the same object type but
there are very serious advantages to allowing a mixed type operation such as
a data.frame where each column is a hidden vector of some type or even at
times to allowing every cell/item to be of any object type. The overhead
rises in terms of storage and CPU time used but it allows higher levels of
abstraction and often the ability to write code with fewer lines that
handles many more conditions, sometimes invisibly. 

Consider how computing is being used and ask if a little more carbon
footprint there may reduce the carbon footprint elsewhere. Would you rather
have people spend years or months developing some app that can be used in a
way that reduces overall carbon dioxide production?

If your answer is that you can have it both ways, fine. But you may have
trouble hiring enough people willing to work under those constraints and you
may be told of lots of things they won't feel comfortable doing and it may
take longer and ...

A question. Are recent compiled languages that add features as small and
fast as earlier ones? For example, many older languages required a function
to take a fixed number of arguments in a fixed order and of exactly the
types mentioned when created. Some interpreted languages allow lots of
additional functionality, some of which could easily be provided such as
allowing named arguments in any order, or allowing additional optional
arguments or default values and so on. Much of this could be done in a
compiled way, but with additional compile time and even run-time cost. But
some features, by definition, must be at run time and especially for code
that modifies itself or creates new objects dynamically. IF you want some of
these new features, how would you supply them in a compiled way without
adding lots of the overhead you want to reduce? 

Carbon guilt should not be taken seriously as an immediate goal as compared
to an overall goal. If we make more people able to work from home or nearby
offices and avoid long commutes, does it matter if your remote work is much
more carbon friendly than the costs to travel and then still use other
energy there for lighting and more computers and ...




-Original Message-
From: Python-list  On
Behalf Of Peter Pearson
Sent: Saturday, October 10, 2020 11:58 AM
To: python-list@python.org
Subject: Python's carbon guilt

Python advocates might want to organize their thoughts on this subject
before their bosses spring the suggestion:

From
https://www.sciencemag.org/news/2020/10/we-re-part-problem-astronomers-confr
ont-their-role-and-vulnerability-climate-change :

. . . Astronomers should also abandon popular programming languages
such as Python in favor of efficient compiled languages. Languages
such as Fortran and C++, Zwart calcu

Re: Python's carbon guilt

2020-10-10 Thread Marco Sulla
He should also calculate the carbon dioxide emitted by brains that
works in C++ only. I omit other sources.
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Re: Python's carbon guilt

2020-10-10 Thread Chris Angelico
On Sun, Oct 11, 2020 at 3:01 AM Peter Pearson  wrote:
>
> Python advocates might want to organize their thoughts on
> this subject before their bosses spring the suggestion:
>
> From 
> https://www.sciencemag.org/news/2020/10/we-re-part-problem-astronomers-confront-their-role-and-vulnerability-climate-change
>  :
>
> . . . Astronomers should also abandon popular programming languages
> such as Python in favor of efficient compiled languages. Languages
> such as Fortran and C++, Zwart calculates, are more than 100 times
> more carbon efficient than Python because they require fewer
> operations.
>
>

Ahh, yes, a new way for people to worship the little tin god. How cute.

:)

ChrisA
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Re: Python's carbon guilt

2020-10-10 Thread Peter J. Holzer
On 2020-10-10 15:58:18 +, Peter Pearson wrote:
> Python advocates might want to organize their thoughts on
> this subject before their bosses spring the suggestion:
> 
> From 
> https://www.sciencemag.org/news/2020/10/we-re-part-problem-astronomers-confront-their-role-and-vulnerability-climate-change
>  :
> 
> . . . Astronomers should also abandon popular programming languages
> such as Python in favor of efficient compiled languages. Languages
> such as Fortran and C++, Zwart calculates, are more than 100 times
> more carbon efficient than Python because they require fewer
> operations.
> 

It would be interesting on which data he based these calculations. For
simple benchmarks of numerical code that's almost certainly true, but I
doubt anyone writes code intended to run on a supercomputer in plain
Python. Surely such programs would use numpy or other specialized
libraries which are already written in C or Fortran and may even use a
GPU if present? There is of course still some overhead, but it's much
smaller.

hp

-- 
   _  | Peter J. Holzer| Story must make more sense than reality.
|_|_) ||
| |   | h...@hjp.at |-- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |   challenge!"


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Python's carbon guilt

2020-10-10 Thread Peter Pearson
Python advocates might want to organize their thoughts on
this subject before their bosses spring the suggestion:

>From 
>https://www.sciencemag.org/news/2020/10/we-re-part-problem-astronomers-confront-their-role-and-vulnerability-climate-change
> :

. . . Astronomers should also abandon popular programming languages
such as Python in favor of efficient compiled languages. Languages
such as Fortran and C++, Zwart calculates, are more than 100 times
more carbon efficient than Python because they require fewer
operations.


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