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Groups > comp.lang.python > #94541 > unrolled thread

Python Questions - July 25, 2015

Started by"E.D.G." <edgrsprj@ix.netcom.com>
First post2015-07-25 04:39 -0500
Last post2015-07-29 00:43 -0700
Articles 20 on this page of 42 — 13 participants

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Contents

  Python Questions - July 25, 2015 "E.D.G." <edgrsprj@ix.netcom.com> - 2015-07-25 04:39 -0500
    Python Questions - July 25, 2015 tandrewjohnson@outlook.com - 2015-07-25 04:36 -0700
      Python Questions - July 25, 2015 tandrewjohnson@outlook.com - 2015-07-25 04:39 -0700
      Re: Python Questions - July 25, 2015 "E.D.G." <edgrsprj@ix.netcom.com> - 2015-07-25 08:16 -0500
        Re: Python Questions - July 25, 2015 Laura Creighton <lac@openend.se> - 2015-07-25 15:59 +0200
          Re: Python Questions - July 25, 2015 "E.D.G." <edgrsprj@ix.netcom.com> - 2015-07-26 12:49 -0500
            Re: Python Questions - July 25, 2015 Laura Creighton <lac@openend.se> - 2015-07-26 20:38 +0200
              Re: Python Questions - July 25, 2015 "E.D.G." <edgrsprj@ix.netcom.com> - 2015-07-26 13:48 -0500
      Re: Python Questions - July 25, 2015 BartC <bc@freeuk.com> - 2015-07-26 13:49 +0100
        Re: Python Questions - July 25, 2015 Chris Angelico <rosuav@gmail.com> - 2015-07-26 23:07 +1000
          Re: Python Questions - July 25, 2015 BartC <bc@freeuk.com> - 2015-07-26 15:30 +0100
        Re: Python Questions - July 25, 2015 Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-07-26 14:19 +0100
        Re: Python Questions - July 25, 2015 Steven D'Aprano <steve@pearwood.info> - 2015-07-27 00:22 +1000
          Re: Python Questions - July 25, 2015 BartC <bc@freeuk.com> - 2015-07-26 15:58 +0100
        Re: Python Questions - July 25, 2015 Rob Gaddi <rgaddi@technologyhighland.invalid> - 2015-07-27 23:14 +0000
          Re: Python Questions - July 25, 2015 Terry Reedy <tjreedy@udel.edu> - 2015-07-28 04:50 -0400
            Re: Python Questions - July 25, 2015 BartC <bc@freeuk.com> - 2015-07-28 10:46 +0100
              Re: Python Questions - July 25, 2015 Chris Angelico <rosuav@gmail.com> - 2015-07-28 20:17 +1000
                Re: Python Questions - July 25, 2015 BartC <bc@freeuk.com> - 2015-07-28 11:44 +0100
                  Re: Python Questions - July 25, 2015 Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-07-28 13:47 +0100
                  Re: Python Questions - July 25, 2015 Steven D'Aprano <steve@pearwood.info> - 2015-07-29 02:02 +1000
              Re: Python Questions - July 25, 2015 Steven D'Aprano <steve@pearwood.info> - 2015-07-29 02:12 +1000
                Re: Python Questions - July 25, 2015 BartC <bc@freeuk.com> - 2015-07-28 17:45 +0100
                  Re: Python Questions - July 25, 2015 Rob Gaddi <rgaddi@technologyhighland.invalid> - 2015-07-28 18:46 +0000
                  Re: Python Questions - July 25, 2015 Laura Creighton <lac@openend.se> - 2015-07-29 18:13 +0200
                    Re: Python Questions - July 25, 2015 BartC <bc@freeuk.com> - 2015-07-29 17:50 +0100
            Re: Python Questions - July 25, 2015 wxjmfauth@gmail.com - 2015-07-28 07:09 -0700
          Re: Python Questions - July 25, 2015 Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-07-28 13:58 +0100
    Re: Python Questions - July 25, 2015 Laura Creighton <lac@openend.se> - 2015-07-25 15:30 +0200
      Re: Python Questions - July 25, 2015 "E.D.G." <edgrsprj@ix.netcom.com> - 2015-07-25 08:45 -0500
    Re: Python Questions - July 25, 2015 tjohnson <tandrewjohnson@outlook.com> - 2015-07-25 15:16 -0700
    Re: Python Questions - July 25, 2015 "E.D.G." <edgrsprj@ix.netcom.com> - 2015-07-26 14:17 -0500
      Re: Python Questions - July 25, 2015 mm0fmf <none@mailinator.com> - 2015-07-26 22:15 +0100
        Re: Python Questions - July 25, 2015 "E.D.G." <edgrsprj@ix.netcom.com> - 2015-07-26 17:08 -0500
          Re: Python Questions - July 25, 2015 "E.D.G." <edgrsprj@ix.netcom.com> - 2015-07-26 17:32 -0500
        Re: Python Questions - July 25, 2015 Ned Batchelder <ned@nedbatchelder.com> - 2015-07-26 16:12 -0700
          Re: Python Questions - July 25, 2015 "E.D.G." <edgrsprj@ix.netcom.com> - 2015-07-26 18:58 -0500
            Re: Python Questions - July 25, 2015 Laura Creighton <lac@openend.se> - 2015-07-27 11:15 +0200
          Re: Python Questions - July 25, 2015 Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-07-27 01:18 +0100
            Re: Python Questions - July 25, 2015 mm0fmf <none@mailinator.com> - 2015-07-27 17:46 +0100
      Re: Python Questions - July 25, 2015 tjohnson <tandrewjohnson@outlook.com> - 2015-07-27 03:24 -0700
        Re: Python Questions - July 25, 2015 wxjmfauth@gmail.com - 2015-07-29 00:43 -0700

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#94700

FromSteven D'Aprano <steve@pearwood.info>
Date2015-07-29 02:02 +1000
Message-ID<55b7a798$0$1636$c3e8da3$5496439d@news.astraweb.com>
In reply to#94689
On Tue, 28 Jul 2015 08:44 pm, BartC wrote:

> No, I asked for how to install numpy, and was told to install Anaconda.
> I didn't know it was so big. It's like asking where to buy a pint of
> milk, and inadvertently buying the whole store! Which does, after all,
> come with the milk I wanted...

Bart, you can't blame us for your failure to do your own investigation
before clicking Download. Don't you read the instructions?

Anaconda installs a full-featured scientific Python stack, not just numpy.
The *very first paragraph* of the download page says:

"It includes over 195 of the most popular Python packages for science, math,
engineering, data analysis."

http://continuum.io/downloads

If the installer is 300MB or so, what were you expecting the full
installation to be? Further down on that same page, it describes Miniconda,
which is a bare-bones installation of Python + the conda package manager
only, so you can pick and choose which of those 195 packages are installed.



-- 
Steven

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#94701

FromSteven D'Aprano <steve@pearwood.info>
Date2015-07-29 02:12 +1000
Message-ID<55b7a9f5$0$1668$c3e8da3$5496439d@news.astraweb.com>
In reply to#94687
On Tue, 28 Jul 2015 07:46 pm, BartC wrote:

> (I'm still reeling from the size of that Anaconda download. Apparently
> it contains a whole bunch of stuff, nothing to do with numpy, that I
> don't need. But one of the listed packages was 'libffi', which is
> puzzling. This library lets a C-like language call functions with
> runtime-determined argument types. How would that be used in Python?)

https://en.wikipedia.org/wiki/Libffi




-- 
Steven

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#94702

FromBartC <bc@freeuk.com>
Date2015-07-28 17:45 +0100
Message-ID<jkOtx.42040$Ec3.13257@fx24.am4>
In reply to#94701
On 28/07/2015 17:12, Steven D'Aprano wrote:
> On Tue, 28 Jul 2015 07:46 pm, BartC wrote:
>
>> (I'm still reeling from the size of that Anaconda download. Apparently
>> it contains a whole bunch of stuff, nothing to do with numpy, that I
>> don't need. But one of the listed packages was 'libffi', which is
>> puzzling. This library lets a C-like language call functions with
>> runtime-determined argument types. How would that be used in Python?)
>
> https://en.wikipedia.org/wiki/Libffi

Yes, I know (I was looking at it myself a few days ago for another 
project). But while it might be used for implementing some of Python's 
internals, I was wondering what it was doing in a user-level set of 
libraries, given that it's mostly a bunch of C code.

Perhaps they were just padding the list to make it look more impressive.

-- 
Bartc

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#94703

FromRob Gaddi <rgaddi@technologyhighland.invalid>
Date2015-07-28 18:46 +0000
Message-ID<mp8im6$knj$3@dont-email.me>
In reply to#94702
On Tue, 28 Jul 2015 17:45:00 +0100, BartC wrote:

> On 28/07/2015 17:12, Steven D'Aprano wrote:
>> On Tue, 28 Jul 2015 07:46 pm, BartC wrote:
>>
>>> (I'm still reeling from the size of that Anaconda download. Apparently
>>> it contains a whole bunch of stuff, nothing to do with numpy, that I
>>> don't need. But one of the listed packages was 'libffi', which is
>>> puzzling. This library lets a C-like language call functions with
>>> runtime-determined argument types. How would that be used in Python?)
>>
>> https://en.wikipedia.org/wiki/Libffi
> 
> Yes, I know (I was looking at it myself a few days ago for another
> project). But while it might be used for implementing some of Python's
> internals, I was wondering what it was doing in a user-level set of
> libraries, given that it's mostly a bunch of C code.
> 
> Perhaps they were just padding the list to make it look more impressive.

It underpins the ctypes implementation, which is neither here nor there.

If I remember right, numpy does dynamic loading of one of a couple 
different (FORTRAN?) algebra libraries depending on which ones it can 
find installed.  That would be a pretty clear use case for libffi.

-- 
Rob Gaddi, Highland Technology -- www.highlandtechnology.com
Email address domain is currently out of order.  See above to fix.

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#94740

FromLaura Creighton <lac@openend.se>
Date2015-07-29 18:13 +0200
Message-ID<mailman.1073.1438186424.3674.python-list@python.org>
In reply to#94702
In a message of Tue, 28 Jul 2015 17:45:00 +0100, BartC writes:
>On 28/07/2015 17:12, Steven D'Aprano wrote:
>> On Tue, 28 Jul 2015 07:46 pm, BartC wrote:
>>
>>> (I'm still reeling from the size of that Anaconda download. Apparently
>>> it contains a whole bunch of stuff, nothing to do with numpy, that I
>>> don't need. But one of the listed packages was 'libffi', which is
>>> puzzling. This library lets a C-like language call functions with
>>> runtime-determined argument types. How would that be used in Python?)
>>
>> https://en.wikipedia.org/wiki/Libffi
>
>Yes, I know (I was looking at it myself a few days ago for another 
>project). But while it might be used for implementing some of Python's 
>internals, I was wondering what it was doing in a user-level set of 
>libraries, given that it's mostly a bunch of C code.
>
>Perhaps they were just padding the list to make it look more impressive.

People who use numpy also want to load up their c extensions a
whole lot.  If you have a hunk of C code (a library, ususually) and
you want to call it from your python code, and play with its
objects just like they were python objects, this is one of the
most common ways to do this.

Laura

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#94743

FromBartC <bc@freeuk.com>
Date2015-07-29 17:50 +0100
Message-ID<Av7ux.44257$Ec3.34720@fx24.am4>
In reply to#94740
On 29/07/2015 17:13, Laura Creighton wrote:
> In a message of Tue, 28 Jul 2015 17:45:00 +0100, BartC writes:
>> On 28/07/2015 17:12, Steven D'Aprano wrote:

>>> https://en.wikipedia.org/wiki/Libffi
>>
>> Yes, I know (I was looking at it myself a few days ago for another
>> project). But while it might be used for implementing some of Python's
>> internals, I was wondering what it was doing in a user-level set of
>> libraries, given that it's mostly a bunch of C code.
>>
>> Perhaps they were just padding the list to make it look more impressive.
>
> People who use numpy also want to load up their c extensions a
> whole lot.  If you have a hunk of C code (a library, ususually) and
> you want to call it from your python code, and play with its
> objects just like they were python objects, this is one of the
> most common ways to do this.

If it's in the form where you start by writing along the lines of:

  import libffi

then it must be something very different to what I looked at. (Which 
seemed to consists of lots of C files, headers and ASM modules, for 
dozens of different targets and compilers.)

I would also expect a foreign-function interface to be built-in, or to 
have all the details taken care of by an add-on, so that the very low 
level libffi wouldn't figure at all.

-- 
Bartc

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#94694

Fromwxjmfauth@gmail.com
Date2015-07-28 07:09 -0700
Message-ID<0ee54fc1-4457-4804-a53d-66f4118a9181@googlegroups.com>
In reply to#94685
Le mardi 28 juillet 2015 10:51:23 UTC+2, Terry Reedy a écrit :
> On 7/27/2015 7:14 PM, Rob Gaddi wrote:
> > On Sun, 26 Jul 2015 13:49:57 +0100, BartC wrote:
> >> How do you actually install Numpy in Windows?
> 
> I believe 'pip install numpy' works
> 
> > As I recall you noodle around with it for a few hours making things that
> > look like progress but turn out to be rabbit holes.
> 
> To me, this is nonsense.  If the above does not work, go to
> http://www.lfd.uci.edu/~gohlke/pythonlibs/
> 
> One of the above worked for me a year ago.  10 minutes max.
> 
> -- 
> Terry Jan Reedy

All this stuff became and is becoming a huge and
unsuable mess.

You should not believe, you should know.

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#94691

FromMark Lawrence <breamoreboy@yahoo.co.uk>
Date2015-07-28 13:58 +0100
Message-ID<mailman.1047.1438088301.3674.python-list@python.org>
In reply to#94680
On 28/07/2015 09:50, Terry Reedy wrote:
> On 7/27/2015 7:14 PM, Rob Gaddi wrote:
>> On Sun, 26 Jul 2015 13:49:57 +0100, BartC wrote:
>>> How do you actually install Numpy in Windows?
>
> I believe 'pip install numpy' works
>
>> As I recall you noodle around with it for a few hours making things that
>> look like progress but turn out to be rabbit holes.
>
> To me, this is nonsense.  If the above does not work, go to
> http://www.lfd.uci.edu/~gohlke/pythonlibs/
>
> One of the above worked for me a year ago.  10 minutes max.
>

You are able to use pip to go directly to sites to get files, which is 
extremely useful if you don't have Visual Studio and hence need to 
bypass the files directly available from pypi.  I've used the following 
successfuly to get the Phoenix (Python 3) version of wxPython.

pip install --trusted-host wxPython.org -U --pre -f 
http://wxPython.org/Phoenix/snapshot-builds/ wxPython_Phoenix

So in theory you should be able to go straight to pythonlibs although 
I've not tried it myself.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence

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#94549

FromLaura Creighton <lac@openend.se>
Date2015-07-25 15:30 +0200
Message-ID<mailman.977.1437831069.3674.python-list@python.org>
In reply to#94541
I can answer some of these.

In a message of Sat, 25 Jul 2015 04:39:43 -0500, "E.D.G." writes:
>       At the moment our Perl programs use Windows "Pipes" plus files in an 
>interactive mode to send data to Gnuplot so that the data can be plotted. 
>That actually produces good results.  But it is a complex and inefficient 
>process.  So part of the conversion process involves learning how to have 
>Python or some other program plot data in the same interactive mode.

check out
matplotlib http://matplotlib.org/
mayavi http://docs.enthought.com/mayavi/mayavi/
bokeh http://bokeh.pydata.org/en/latest/
seaborn: http://stanford.edu/~mwaskom/software/seaborn/

There are others.
It sounds to me as if bokeh or mayavi animations are what you will
be most interested in, but we can discuss this more.

>1. The initial version of Python being used has to be a free download that 
>is easy to understand.  And it has to be compatible with Windows.
>
>       Where can the best free download version of Python be obtained?
>
>       Is the ActiveState version the best one for people who are not Python 
>experts?

For you, I think not.  Your use case sounds like you are seriously on
the 'scientific python' end of things.  So you would be most interested
in installing either the Enthought Scientific Python Collection (Canopy)
https://store.enthought.com/

Or the Anaconda Scientific Python Suite:
https://store.continuum.io/cshop/anaconda/

Enthought has been the leader in Scientific Python for many, many years.
Anaconda is the new kid on the block.  I cannot state which is better --
Anaconda is what we are using here at Chalmers University for the most
part.

They both duplicate the same functionality, for the most part, but
the conda package manager that comes with Anaconda is really terrific.

They bundle in all sorts of graphics and visualisation things.  This
is where you should start your looking.

>2.  Graphics - This is likely a fairly complicated question.
>
>       What are some of the graphics options available with Python?

see Anaconda and Enthought for a good start.  If they don't do what
you want, come back and discuss this more, we have plenty more
options.

>3.  Fast Calculations
>
>       It is my expectation that Python by itself does not do calculations 
>very fast when compared to a language such as Fortran.

For the C version of Python, yes.  There are many options for speeding
up your python, but for your purposes numpy -- which is integrated into
both the Enthought and Anaconda distribuitions is likely to be the
most useful.  You can also integrate with Fortran libraries should
you want to here.

>4. What is the code for opening a Windows "Pipe" between a running Python 
>program and some other program such as another Python or Perl program that 
>can work with pipes?

No, clue, I don't know very much at all about Windows.

>5. We would want Python to check for a key press now and then without 
>actually waiting until a key is pressed.  What would be the command for 
>that?  It is likely something like Get_Key

Python knows _nothing_ about keys, keyboard input and the like.
Capturing that stuff is the function of the graphical user interface
program you use.  Python has many of these.  They all do it slightly
differently but you won't have any problems whatever one you pick.

>6. What is Python's version of the DOS level "System" command that many 
>programs use as in:
>
>system "open notepad.exe"

Again, not a windows person but I am pretty sure you are looking for the
subprocess module:

For Python 2
https://docs.python.org/2/library/subprocess.html#module-subprocess
For Python 3
https://docs.python.org/3.5/library/subprocess.html#module-subprocess

>7. What is Python's version of the SendKey command that many programs use to 
>send information to an active Windows program as in:
>
>SendKey("Message to be printed on the Notepad screen")
>
>or
>
>SendKey(Right Arrow Key)

We don't have one.  You have to talk to your GUI toolkit for this.

>8. What commands does Python use to send to, and retrieve information from, 
>the Windows clipboard?

I don't know, again, I  think you have to talk to your GUI toolkit.

So, if I were you I would go check out the Enthought and Anaconda links
and see if you like what they have to offer.  What Gui toolkit you should
use is partly a matter of personal preference, but often a matter of
what kit works best with whatever visualisation tool you choose.

In terms of the talking to people who heavily use the graphics toolkits
mentioned, well, this list isn't a bad place to look for people but
The scientific Python mailing list may get be a better place.

http://www.scipy.org/scipylib/mailing-lists.html

Anaconda also has a google group
https://groups.google.com/a/continuum.io/forum/#!forum/anaconda

And, of course, the various visualisers have their own mailing lists
and forums which may be of use.

Hope this helps,
come back with any more questions
Laura Creighton

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#94551

From"E.D.G." <edgrsprj@ix.netcom.com>
Date2015-07-25 08:45 -0500
Message-ID<l-CdndNp2vR_Dy7InZ2dnUU7-dmdnZ2d@earthlink.com>
In reply to#94549
"Laura Creighton" <lac@openend.se> wrote in message 
news:mailman.977.1437831069.3674.python-list@python.org...
>I can answer some of these.


Posted by E.D.G.   July 25, 2015

       Thanks for all of the comments.  My retired professional programming 
colleague is now going to have plenty of projects to work on.  I myself am 
neither retired nor a professional programmer and usually rely on him to do 
the programming language exploration work.

       Most of those "system," "Pipe", and "SendKey" type commands usually 
refer to programs that are going to be running in a Windows environment. 
And many or most of the experienced programmers who are using Perl, Python, 
or Fortran appear to me to be using UNIX or Linux.  So they might not be 
familiar with some Windows related commands such as "system."  It took me a 
long, long time to learn how to get the Perl versions of those commands to 
work.

Regards,

E.D.G.

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#94579

Fromtjohnson <tandrewjohnson@outlook.com>
Date2015-07-25 15:16 -0700
Message-ID<36504953-b446-4ec5-a3ff-8ba4fc746a99@googlegroups.com>
In reply to#94541
On Saturday, July 25, 2015 at 5:40:02 AM UTC-4, E.D.G. wrote:
> Posted by E.D.G. July 25, 2015
> 
>        This posting involves general interest matters and some specific 
> questions regarding Python code usage.  Any help would be appreciated.
> 
> 1. Program conversion effort
> 2. Specific code questions
> 
> 
> 1.  PROGRAM CONVERSION EFFORT
> 
>        An effort is underway by several people including myself to convert a 
> complex Perl language program to some other language such as Python so that, 
> among other things, the program's numerous calculations will run faster.
> 
>        Perl with the PDL module would probably work.  But we could not get 
> the needed type of support for the PDL module.  We also looked at Julia and 
> several versions of Basic.  But they also did not appear to presently have 
> the type of support that is needed.
> 
>        Fortran was tried.  It is great for calculation speed and the Fortran 
> users were quite helpful.  But we could not get certain important questions 
> answered regarding using Fortran to create Windows "Pipes" to other running 
> programs etc.
> 
>        We are presently checking to see if Python has the needed features 
> and adequate support from Python newsgroups or forums.
> 
>        At the moment our Perl programs use Windows "Pipes" plus files in an 
> interactive mode to send data to Gnuplot so that the data can be plotted. 
> That actually produces good results.  But it is a complex and inefficient 
> process.  So part of the conversion process involves learning how to have 
> Python or some other program plot data in the same interactive mode.
> 
>        In this case "interactive" means that when a chart is being displayed 
> on the computer screen for example, a key such as a Right Arrow Key can be 
> pressed.  My main Perl program checks for key presses perhaps 10 times a 
> second and if it detects one it sends the appropriate information to Gnuplot 
> through a "Pipe" so that Gnuplot will open some data file and use its 
> contents to draw a new chart.  That redrawing process on a moderately fast 
> computer occurs so rapidly the transition cannot even be seen.
> 
>        The Perl program does not simply wait for a key to be pressed because 
> it is at times processing data in the background.
> 
>        It has been my experience that sending large amounts of data from one 
> program to another using a Windows pipe doesn't work very well.  So files 
> are presently being used for bulk data transfers.
> 
> 
> 2.  SPECIFIC CODE QUESTIONS
> 
>        It will likely take some time to get all of these questions 
> completely answered, especially the ones involving graphics.
> 
> 
> 1. The initial version of Python being used has to be a free download that 
> is easy to understand.  And it has to be compatible with Windows.
> 
>        Where can the best free download version of Python be obtained?
> 
>        Is the ActiveState version the best one for people who are not Python 
> experts?
> 
>        I always found it quite easy to install ActiveState versions of Perl.
> 
> 
> 2.  Graphics - This is likely a fairly complicated question.
> 
>        What are some of the graphics options available with Python?
> 
>        Does it have its own internal graphics routines?  Perl does not as 
> far as I can tell.  And we never had time to explore Fortran's graphics 
> capabilities.
> 
>        I am aware of the existence of Matlab.  But as stated, everything 
> involved with this present effort has to be a free download so that 
> programmers around the world can easily and inexpensively generate program 
> subroutines etc.
> 
> 
> 3.  Fast Calculations
> 
>        It is my expectation that Python by itself does not do calculations 
> very fast when compared to a language such as Fortran.
> 
>        So, what options are available for increasing the speed of Python 
> calculations?
> 
>        Python could call a Fortran program to do the calculations just as 
> Perl could.  But we would like to avoid having to use more than one language 
> with this effort.
> 
> 
> 4. What is the code for opening a Windows "Pipe" between a running Python 
> program and some other program such as another Python or Perl program that 
> can work with pipes?
> 
>        Three examples are needed if possible, one for just sending, one for 
> just receiving, and one that allows both sending and receiving.  I know how 
> to open Windows pipes using Perl.
> 
> 
> 5. We would want Python to check for a key press now and then without 
> actually waiting until a key is pressed.  What would be the command for 
> that?  It is likely something like Get_Key
> 
> 
> 6. What is Python's version of the DOS level "System" command that many 
> programs use as in:
> 
> system "open notepad.exe"
> 
> 
> 7. What is Python's version of the SendKey command that many programs use to 
> send information to an active Windows program as in:
> 
> SendKey("Message to be printed on the Notepad screen")
> 
> or
> 
> SendKey(Right Arrow Key)
> 
> 
> 8. What commands does Python use to send to, and retrieve information from, 
> the Windows clipboard?
> 
> 
>        Regards, and thanks again for any assistance with this.
> 
> E.D.G.

It looks like Laura has answered most of your questions pretty well. I'm sorry that I forgot about your questions until now. I was busy because the hard drive on my primary PC failed last night.

The only thing I can think of right now to add is that regarding #8, you can also use the PyWin32 module on Windows for clipboard access. If your code needs to be cross-platform, this isn't an option, but if not, you might find it to be very useful. It might also have capabilities for #3 and #7, but I don't have it installed anymore, so I'm not sure.

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#94645

From"E.D.G." <edgrsprj@ix.netcom.com>
Date2015-07-26 14:17 -0500
Message-ID<ks2dnVPporT-ryjInZ2dnUU7-W2dnZ2d@earthlink.com>
In reply to#94541
"E.D.G." <edgrsprj@ix.netcom.com> wrote in message 
news:jf6dnQiMOZ_GxC7InZ2dnUU7-S2dnZ2d@earthlink.com...

Posted by E.D.G.   July 26, 2015

        These are some additional comments related to my original post.

       The effort I have been discussing actually involves developing a 
totally free version of some language that scientists around the world could 
easily install and use.


1.  With my own science related Perl programs I provide people with .exe 
versions in addition to the .pl versions.  And for the .pl versions, at one 
of my Web sites there is actually an entire Perl programming language 
directory available in a .zip package.  So, people can download the file, 
unzip it, and then save it as the Perl directory and .pl programs will then 
run on that computer.  We would like to be able to do the same thing with 
Python if we start working with that language.  And a response in another 
post indicates that this should be possible.

2.  Python looks especially attractive because so many people are using it. 
And I myself have a friend who is a very experienced professional Python 
programmer.  On the other hand, there are so many versions of Python that it 
might be difficult at first to determine which one to start with.

3.  I asked that Python programmer if Python could run on an Internet server 
as a CGI program.  And the answer was "I have no idea."  So, amusingly, 
apparently even experienced professional programmers don't know everything 
there is to know about a given programming language!

4.  I myself know that Perl programs will run on Internet servers as CGI 
programs and have written several myself using a development program called 
Xampp to create and test them before installing them on the server computer.

5.  My retired professional programming colleague has now told me that he 
downloaded and installed the ActiveState Windows version of Python with no 
difficulties.  So, that is encouraging news.

6.  He said that he is looking around for a good IDE for Python and found 
one called "Eric" that he is checking.

7.  With my Perl language programs I have developed a resource that will do 
the following.  And I imagine that this could also be done with Python. 
This resource can't be developed with many and probably most programming 
languages.

       In part because of limited calculation speeds it can take one of my 
important probability calculation Perl programs as much a two hours to run 
and create all of the necessary data arrays.  Many, many millions of 
calculations are involved.  And once everything is set, for time limitation 
reasons it would be ordinarily be impossible to make any changes to the data 
or to the original program code without losing all of the data.

       So, I have developed a special Perl program that makes that possible. 
And as I said, I am guessing that this approach would also work with Python.

       When the Perl program is done with its calculations, instead of 
ending it jumps to another Perl program.  But all of the data in the arrays 
it created remain active in memory.  The original program code can then be 
changed.  The second Perl program is then told that the changes are complete 
and that it should return to the first program.  Perl then attempt to 
recompile the original code.  If it is successful it then uses the new code 
and does whatever is specified.  The previously created arrays are still 
active in memory using the same array names etc.

       If there was an error in the new code, a Windows screen appears 
explaining that there was an error and the compilation ends.  But, the data 
remain in the active computer memory.

       Changes can then be are made to the program code to fix the error. 
And, the second Perl program is told to try again.  If there are no new 
errors the first program recompiles and runs using the already created 
arrays etc.

      This is a very useful resource for scientists as it lets them create 
and test new program code without having to recreate all of the data arrays. 
And as I stated, it would probably not be possible to develop such a 
resource with most programming languages.

Regards,

E.D.G.

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#94648

Frommm0fmf <none@mailinator.com>
Date2015-07-26 22:15 +0100
Message-ID<J5ctx.20800$IK6.11473@fx46.am4>
In reply to#94645
On 26/07/2015 20:17, E.D.G. wrote:
> "E.D.G." <edgrsprj@ix.netcom.com> wrote in message
> news:jf6dnQiMOZ_GxC7InZ2dnUU7-S2dnZ2d@earthlink.com...
>
> Posted by E.D.G.   July 26, 2015
>
>         These are some additional comments related to my original post.
>
>        The effort I have been discussing actually involves developing a
> totally free version of some language that scientists around the world
> could easily install and use.
>
>
> 1.  With my own science related Perl programs I provide people with .exe
> versions in addition to the .pl versions.  And for the .pl versions, at
> one of my Web sites there is actually an entire Perl programming
> language directory available in a .zip package.  So, people can download
> the file, unzip it, and then save it as the Perl directory and .pl
> programs will then run on that computer.  We would like to be able to do
> the same thing with Python if we start working with that language.  And
> a response in another post indicates that this should be possible.
>
> 2.  Python looks especially attractive because so many people are using
> it. And I myself have a friend who is a very experienced professional
> Python programmer.  On the other hand, there are so many versions of
> Python that it might be difficult at first to determine which one to
> start with.
>
> 3.  I asked that Python programmer if Python could run on an Internet
> server as a CGI program.  And the answer was "I have no idea."  So,
> amusingly, apparently even experienced professional programmers don't
> know everything there is to know about a given programming language!
>
> 4.  I myself know that Perl programs will run on Internet servers as CGI
> programs and have written several myself using a development program
> called Xampp to create and test them before installing them on the
> server computer.
>
> 5.  My retired professional programming colleague has now told me that
> he downloaded and installed the ActiveState Windows version of Python
> with no difficulties.  So, that is encouraging news.
>
> 6.  He said that he is looking around for a good IDE for Python and
> found one called "Eric" that he is checking.
>
> 7.  With my Perl language programs I have developed a resource that will
> do the following.  And I imagine that this could also be done with
> Python. This resource can't be developed with many and probably most
> programming languages.
>
>        In part because of limited calculation speeds it can take one of
> my important probability calculation Perl programs as much a two hours
> to run and create all of the necessary data arrays.  Many, many millions
> of calculations are involved.  And once everything is set, for time
> limitation reasons it would be ordinarily be impossible to make any
> changes to the data or to the original program code without losing all
> of the data.
>
>        So, I have developed a special Perl program that makes that
> possible. And as I said, I am guessing that this approach would also
> work with Python.
>
>        When the Perl program is done with its calculations, instead of
> ending it jumps to another Perl program.  But all of the data in the
> arrays it created remain active in memory.  The original program code
> can then be changed.  The second Perl program is then told that the
> changes are complete and that it should return to the first program.
> Perl then attempt to recompile the original code.  If it is successful
> it then uses the new code and does whatever is specified.  The
> previously created arrays are still active in memory using the same
> array names etc.
>
>        If there was an error in the new code, a Windows screen appears
> explaining that there was an error and the compilation ends.  But, the
> data remain in the active computer memory.
>
>        Changes can then be are made to the program code to fix the
> error. And, the second Perl program is told to try again.  If there are
> no new errors the first program recompiles and runs using the already
> created arrays etc.
>
>       This is a very useful resource for scientists as it lets them
> create and test new program code without having to recreate all of the
> data arrays. And as I stated, it would probably not be possible to
> develop such a resource with most programming languages.
>
> Regards,
>
> E.D.G.
>

Am I the only person thinking Troll?

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#94652

From"E.D.G." <edgrsprj@ix.netcom.com>
Date2015-07-26 17:08 -0500
Message-ID<Q5SdnTejbKKjxyjInZ2dnUU7-TednZ2d@earthlink.com>
In reply to#94648
"mm0fmf" <none@mailinator.com> wrote in message 
news:J5ctx.20800$IK6.11473@fx46.am4...
 > Am I the only person thinking Troll?

Posted by E.D.G.   July 26, 2015

       In my opinion, one of the most important aspects in considering the 
selection of a new programming language is the willingness of people posting 
notes to the language's newsgroup to be friendly and cooperative.  And in 
that regard, I have found the Fortran people to be the best.  I never 
encountered an unfriendly note in that newsgroup.  Unfortunately, Fortran 
just "ran out of steam" when it came to Windows applications.

       As far as I can recall, yours is only the second time I have 
encountered a Python newsgroup note that, in my opinion, did not have a 
friendly tone to it.  And if that appears to be the general case here then 
all of the people with whom I work will just dump Python as a language to 
consider.

       The Perl newsgroup is yet another matter.  And we have all largely 
decided to abandon Perl as the language of choice because it has seemed to 
be so difficult to get any help in that newsgroup.

Regards,

E.D.G.

[toc] | [prev] | [next] | [standalone]


#94653

From"E.D.G." <edgrsprj@ix.netcom.com>
Date2015-07-26 17:32 -0500
Message-ID<xaSdnUDKM5NAwijInZ2dnUU7-LOdnZ2d@earthlink.com>
In reply to#94652
"E.D.G." <edgrsprj@ix.netcom.com> wrote in message 
news:Q5SdnTejbKKjxyjInZ2dnUU7-TednZ2d@earthlink.com...

Posted by E.D.G.  July 26, 2015

       There is an additional comment for people who are interested in 
scientific programming efforts.

       Most people are aware that when the U.S. Government tried to get a 
Web site running in connection with the Affordable Care Act a while ago, the 
government Web site crashed.

       One of the major problems with government programming efforts appears 
to me to be the fact that people working in different government agencies 
are often using different programming languages.  And those people don't 
communicate with one another.  The results are inefficiency.

      To demonstrate that the programming effort I am discussing is quite 
serious I am providing the following indirect link.  This is for a proposed 
effort to get as many government scientists etc. as possible connected with 
one another and moving in the same direction at the same time.

http://www.freewebs.com/eq-forecasting/DSAT.html

       If that type of program does eventually get created then the 
government scientists are still going to want some computer language that 
they can all work with.  And an important question at this time is, "Might 
one of the languages of choice be Python?"

Regards,

E.D.G.

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#94654

FromNed Batchelder <ned@nedbatchelder.com>
Date2015-07-26 16:12 -0700
Message-ID<b68af3d4-6f12-49d6-8c15-f18a95441eda@googlegroups.com>
In reply to#94648
On Sunday, July 26, 2015 at 5:15:31 PM UTC-4, mm0fmf wrote:
> On 26/07/2015 20:17, E.D.G. wrote:
> > "E.D.G." <edgrsprj@ix.netcom.com> wrote in message
> > news:jf6dnQiMOZ_GxC7InZ2dnUU7-S2dnZ2d@earthlink.com...
> >
> > Posted by E.D.G.   July 26, 2015
> >
> >         These are some additional comments related to my original post.
> >
> >        The effort I have been discussing actually involves developing a
> > totally free version of some language that scientists around the world
> > could easily install and use.
> >
> >
> > 1.  With my own science related Perl programs I provide people with .exe
> > versions in addition to the .pl versions.  And for the .pl versions, at
> > one of my Web sites there is actually an entire Perl programming
> > language directory available in a .zip package.  So, people can download
> > the file, unzip it, and then save it as the Perl directory and .pl
> > programs will then run on that computer.  We would like to be able to do
> > the same thing with Python if we start working with that language.  And
> > a response in another post indicates that this should be possible.
> >
> > 2.  Python looks especially attractive because so many people are using
> > it. And I myself have a friend who is a very experienced professional
> > Python programmer.  On the other hand, there are so many versions of
> > Python that it might be difficult at first to determine which one to
> > start with.
> >
> > 3.  I asked that Python programmer if Python could run on an Internet
> > server as a CGI program.  And the answer was "I have no idea."  So,
> > amusingly, apparently even experienced professional programmers don't
> > know everything there is to know about a given programming language!
> >
> > 4.  I myself know that Perl programs will run on Internet servers as CGI
> > programs and have written several myself using a development program
> > called Xampp to create and test them before installing them on the
> > server computer.
> >
> > 5.  My retired professional programming colleague has now told me that
> > he downloaded and installed the ActiveState Windows version of Python
> > with no difficulties.  So, that is encouraging news.
> >
> > 6.  He said that he is looking around for a good IDE for Python and
> > found one called "Eric" that he is checking.
> >
> > 7.  With my Perl language programs I have developed a resource that will
> > do the following.  And I imagine that this could also be done with
> > Python. This resource can't be developed with many and probably most
> > programming languages.
> >
> >        In part because of limited calculation speeds it can take one of
> > my important probability calculation Perl programs as much a two hours
> > to run and create all of the necessary data arrays.  Many, many millions
> > of calculations are involved.  And once everything is set, for time
> > limitation reasons it would be ordinarily be impossible to make any
> > changes to the data or to the original program code without losing all
> > of the data.
> >
> >        So, I have developed a special Perl program that makes that
> > possible. And as I said, I am guessing that this approach would also
> > work with Python.
> >
> >        When the Perl program is done with its calculations, instead of
> > ending it jumps to another Perl program.  But all of the data in the
> > arrays it created remain active in memory.  The original program code
> > can then be changed.  The second Perl program is then told that the
> > changes are complete and that it should return to the first program.
> > Perl then attempt to recompile the original code.  If it is successful
> > it then uses the new code and does whatever is specified.  The
> > previously created arrays are still active in memory using the same
> > array names etc.
> >
> >        If there was an error in the new code, a Windows screen appears
> > explaining that there was an error and the compilation ends.  But, the
> > data remain in the active computer memory.
> >
> >        Changes can then be are made to the program code to fix the
> > error. And, the second Perl program is told to try again.  If there are
> > no new errors the first program recompiles and runs using the already
> > created arrays etc.
> >
> >       This is a very useful resource for scientists as it lets them
> > create and test new program code without having to recreate all of the
> > data arrays. And as I stated, it would probably not be possible to
> > develop such a resource with most programming languages.
> >
> > Regards,
> >
> > E.D.G.
> >
> 
> Am I the only person thinking Troll?

Yes.

--Ned.

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#94656

From"E.D.G." <edgrsprj@ix.netcom.com>
Date2015-07-26 18:58 -0500
Message-ID<1c6dnRzGjJyP6SjInZ2dnUU7-S-dnZ2d@earthlink.com>
In reply to#94654
"Ned Batchelder" <ned@nedbatchelder.com> wrote in message 
news:b68af3d4-6f12-49d6-8c15-f18a95441eda@googlegroups.com...
>> Am I the only person thinking Troll?
> Yes.

Posted by E.D.G.   July 26, 2015

       With some humor intended, thanks for the supportive note.

       This is an indirect URL for a potentially important computer program 
that I feel needs to be developed.  Unfortunately, although Python could be 
used to create PC or Mac versions of the program I don't think that those 
programs would run on Internet server computers.  But I don't yet know 
enough about Python to be able to tell if that is the case or not.

http://www.freewebs.com/eq-forecasting/Disaster_Response_System.html

       There are two Perl programs that I have developed that I believe many 
Python users would like to have available in Python versions.  And at some 
point I might create a Web page that will discuss them in detail.  For the 
moment I have just made the decision to combine them into a single program 
that would be quite helpful for the scientific community.  People don't 
actually even need my assistance with developing these types of programs. 
Some versions are likely already available for free.

       The first program can do things such as automatically go to a Web 
site that provides weather information for example, feed information to the 
Web page program running at that site, wait for the results, copy them to a 
PC or Mac, and start processing the data.  It is a tremendously powerful and 
versatile program that can save scientists etc. large amounts of time by 
helping them automate repetitive tasks that take a lot of time if done 
manually.  Microsoft at one time had a Windows program available that did 
things like that.  I seem to remember that it was called "Recorder."  My own 
Perl version of the program is many times more powerful.

       The second program acts as a type of universal communicator for 
Windows programs.  It would actually work with any operating system.

       Running in the background it can start, stop, and interact with any 
Windows compatible programs such as other Perl programs, Notepad.exe, Excel, 
Fortran, Python undoubtedly, and also execute DOS shell commands etc.  With 
word processor programs and spreadsheet programs like Excel it makes life 
much easier as a person needs to learn how to program in only one language 
to get things done instead of all of those individual macro languages.

Regards,

E.D.G.

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#94663

FromLaura Creighton <lac@openend.se>
Date2015-07-27 11:15 +0200
Message-ID<mailman.1029.1437988555.3674.python-list@python.org>
In reply to#94656
In a message of Sun, 26 Jul 2015 18:58:14 -0500, "E.D.G." writes:

>       This is an indirect URL for a potentially important computer program 
>that I feel needs to be developed.  Unfortunately, although Python could be 
>used to create PC or Mac versions of the program I don't think that those 
>programs would run on Internet server computers.  But I don't yet know 
>enough about Python to be able to tell if that is the case or not.

Sure they will.  That thing about the Affordable Health Care Act
you mentioned -- do you know how this got _fixed_?  People in this
community, notably Alex Gaynor went and turned the lot into a
Django Python app.  He's now working for the US department of
Veteran Affairs, turning more things into Django apps so that
veterans can get their claims processed in weeks (they are aiming
for days) rather than 6-8 months which was the norm before he
got their.  His plan is to speed up the US government with Python
one agency at a time.

There are many techniques you can use to make your Python code fast.
I think we are much better off in that regard than the Perl users are.
If you need better than CPython performance, you might be able to just
use numpy numerical arrays and get the improvement you need.  Or you
might just stop using CPython, and use PyPy, which is a completely
different implementation and which has a JIT that gives
rather good performance, often on the order of pure C code.
see http://speed.pypy.org/

Or you can use Cython http://cython.org/ to make C extensions out of
the part of your python code you would like to run faster.  Or maybe
there already is a C or Fortran library that already does what you
want, you just want to use it in your code.  There are techniques for
just doing this -- and if the library is well known then chances are
somebody else has already made python bindings for it so you can just
use it with CPython.

I wouldn't worry about speed.

If you want to reimplement your webscraping Perl program in Python, I
suggest you start with this library http://scrapy.org/ rather than
reinventing things from scratch.  The scrapy community is very happy to
get code with new techniques which they add to the library, and then
we all benefit.

Laura

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#94657

FromMark Lawrence <breamoreboy@yahoo.co.uk>
Date2015-07-27 01:18 +0100
Message-ID<mailman.1021.1437956325.3674.python-list@python.org>
In reply to#94654
On 27/07/2015 00:12, Ned Batchelder wrote:
> On Sunday, July 26, 2015 at 5:15:31 PM UTC-4, mm0fmf wrote:
>> On 26/07/2015 20:17, E.D.G. wrote:

[around 90 lines snipped]

>>
>> Am I the only person thinking Troll?
>
> Yes.
>
> --Ned.
>

Was it really necessary to resend all of the original for the sake of a 
seven word question and a one word answer?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence

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#94669

Frommm0fmf <none@mailinator.com>
Date2015-07-27 17:46 +0100
Message-ID<kfttx.13420$ur5.269@fx20.am4>
In reply to#94657
On 27/07/2015 01:18, Mark Lawrence wrote:
> On 27/07/2015 00:12, Ned Batchelder wrote:
>> On Sunday, July 26, 2015 at 5:15:31 PM UTC-4, mm0fmf wrote:
>>> On 26/07/2015 20:17, E.D.G. wrote:
>
> [around 90 lines snipped]
>
>>>
>>> Am I the only person thinking Troll?
>>
>> Yes.
>>
>> --Ned.
>>
>
> Was it really necessary to resend all of the original for the sake of a
> seven word question and a one word answer?

Yes? ;-)

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