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newbie ``print`` question

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  newbie ``print`` question gwhite <gwhite@ti.com> - 2012-09-02 10:23 -0700
    Re: newbie ``print`` question Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-09-02 18:41 +0100
    Re: newbie ``print`` question Joel Goldstick <joel.goldstick@gmail.com> - 2012-09-02 13:44 -0400
      Re: newbie ``print`` question gwhite <gwhite@ti.com> - 2012-09-02 12:46 -0700
    Re: newbie ``print`` question mblume <foobar@invalid.invalid> - 2012-09-02 17:49 +0000
      Re: newbie ``print`` question gwhite <gwhite@ti.com> - 2012-09-02 11:51 -0700
    Re: newbie ``print`` question Chris Rebert <clp2@rebertia.com> - 2012-09-02 10:55 -0700
      Re: newbie ``print`` question gwhite <gwhite@ti.com> - 2012-09-02 11:51 -0700
      Re: newbie ``print`` question gwhite <gwhite@ti.com> - 2012-09-02 12:26 -0700
        Re: newbie ``print`` question gwhite <gwhite@ti.com> - 2012-09-02 12:34 -0700
          Re: newbie ``print`` question Dave Angel <d@davea.name> - 2012-09-02 15:41 -0400
            Re: newbie ``print`` question gwhite <gwhite@ti.com> - 2012-09-02 12:50 -0700
              Re: newbie ``print`` question Dave Angel <d@davea.name> - 2012-09-02 16:15 -0400
                Re: newbie ``print`` question gwhite <gwhite@ti.com> - 2012-09-02 13:58 -0700
                  Re: newbie ``print`` question MRAB <python@mrabarnett.plus.com> - 2012-09-02 23:43 +0100
                    Re: newbie ``print`` question gwhite <gwhite@ti.com> - 2012-09-02 16:33 -0700
                      Re: newbie ``print`` question MRAB <python@mrabarnett.plus.com> - 2012-09-03 01:12 +0100
        Re: newbie ``print`` question Terry Reedy <tjreedy@udel.edu> - 2012-09-02 16:49 -0400
          Re: newbie ``print`` question gwhite <gwhite@ti.com> - 2012-09-02 14:18 -0700
            Re: newbie ``print`` question Chris Angelico <rosuav@gmail.com> - 2012-09-03 07:47 +1000
              Re: newbie ``print`` question gwhite <gwhite@ti.com> - 2012-09-02 16:20 -0700
                Re: newbie ``print`` question Chris Angelico <rosuav@gmail.com> - 2012-09-03 09:28 +1000
    Re: newbie ``print`` question Terry Reedy <tjreedy@udel.edu> - 2012-09-02 14:33 -0400
      Re: newbie ``print`` question gwhite <gwhite@ti.com> - 2012-09-02 12:18 -0700
    Re: newbie ``print`` question Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-09-02 16:37 -0400
      Re: newbie ``print`` question gwhite <gwhite@ti.com> - 2012-09-02 14:04 -0700

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#28326

On Sep 2, 2:47 pm, Chris Angelico <ros...@gmail.com> wrote:
> On Mon, Sep 3, 2012 at 7:18 AM, gwhite <gwh...@ti.com> wrote:
> > Thanks again, Terry.  There is a lot to the language, I am finding
> > out.  I am a HW engineer, not really a programmer.  Python seems a lot
> > more sophisticated than MATLAB.
>
> > I'm kinda thinking `write` is likely to be a little more "stable" than
> > `print` (if that is the right characterization) when my eventual
> > switch from 2.7 to 3.x happens.  You think?
>
> If you're planning to switch, make use of __future__. It's
> specifically to make that job easier. Once you have a future
> declaration at the top, print() will be stable across 2.7 and 3.x.

I guess you're saying 3.x will just ignore:

from __future__ import print_function

I'll risk being silly, and thus ask: but what if when I get to 3.x
there is no __future__, as it is now "present?"  Do I need to strip
out the line?

What would happen when I finally started running 3.3, and a new
__future__ was made that broke the old syntax?  Do I need to strip out
the line?

I'm probably over thinking it.  I don't know what I am doing.  lol!

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#28327

On Mon, Sep 3, 2012 at 9:20 AM, gwhite <gwhite@ti.com> wrote:
> I guess you're saying 3.x will just ignore:
>
> from __future__ import print_function
>
> I'll risk being silly, and thus ask: but what if when I get to 3.x
> there is no __future__, as it is now "present?"  Do I need to strip
> out the line?
>
> What would happen when I finally started running 3.3, and a new
> __future__ was made that broke the old syntax?  Do I need to strip out
> the line?
>
> I'm probably over thinking it.  I don't know what I am doing.  lol!

The __future__ statement is guaranteed to be supported forever
afterwards. And new ones won't do anything unless you explicitly put
them into your code. It's quite a good system, imo.

ChrisA

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#28287

On 9/2/2012 1:23 PM, gwhite wrote:
> I can't figure out how to stop the "add a space at the beginning"
> behavior of the print function.
>
>>>> print 1,;print 2,
> 1 2

You have discovered why print is a function in 3.x.
 >>> print(1, 2, sep='')
12
 >>> print(1, end=''); print(2, end='')
12

In 2.6 or 2.7, you can add
   from __future__ import print_function
but I recommend using 3.2 or 3.3 unless you have a reason to use older 
Python.



-- 
Terry Jan Reedy

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#28295

On Sep 2, 11:33 am, Terry Reedy <tjre...@udel.edu> wrote:
> On 9/2/2012 1:23 PM, gwhite wrote:
>
> > I can't figure out how to stop the "add a space at the beginning"
> > behavior of the print function.
>
> >>>> print 1,;print 2,
> > 1 2
>
> You have discovered why print is a function in 3.x.
>  >>> print(1, 2, sep='')
> 12
>  >>> print(1, end=''); print(2, end='')
> 12
>
> In 2.6 or 2.7, you can add
>    from __future__ import print_function
> but I recommend using 3.2 or 3.3 unless you have a reason to use older
> Python.
>
> --
> Terry Jan Reedy

Thanks.  I would use 3.2 or 3.3, but I am actually using pythonxy,
which hasn't quite gotten there yet, as the bundle of packages has to
all play nice together. Or so I am guessing.   I have been considering
the __future__ technique.

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#28314

On Sun, 2 Sep 2012 10:23:53 -0700 (PDT), gwhite <gwhite@ti.com>
declaimed the following in gmane.comp.python.general:


> 
> "A space is written before each object is (converted and) written,
> unless the output system believes it is positioned at the beginning of
> a line."
> 
> So it is apparently doing what it is supposed to do.
> 
> Is there a way to stop this?  Or is there a different function that
> will only print what you have in the formatted string?
>
E:\UserData\Wulfraed\My Documents>python
ActivePython 2.7.2.5 (ActiveState Software Inc.) based on
Python 2.7.2 (default, Jun 24 2011, 12:21:10) [MSC v.1500 32 bit
(Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> print "1",;sys.stdout.softspace=0;print "2"
12
>>>
>>> sys.stdout.write("1");sys.stdout.write("2");print
12
>>>

	In Python 2.x, the equivalent of fprint/fprintf is NOT print but
sys.stdout.write/file_object.write

	"print" is just a convenience function that is designed to translate
its arguments into a textual representation, and then drop it to the
screen. Part of the convenience is to separate output items by a space
and to emit a newline at the end.

	.write(), OTOH, does no formatting -- not even new lines. You have
to provide all conversion to text, and line endings.

-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
        wlfraed@ix.netcom.com    HTTP://wlfraed.home.netcom.com/

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#28321

On Sep 2, 1:37 pm, Dennis Lee Bieber <wlfr...@ix.netcom.com> wrote:
> On Sun, 2 Sep 2012 10:23:53 -0700 (PDT), gwhite <gwh...@ti.com>
> declaimed the following in gmane.comp.python.general:
>
>
>
> > "A space is written before each object is (converted and) written,
> > unless the output system believes it is positioned at the beginning of
> > a line."
>
> > So it is apparently doing what it is supposed to do.
>
> > Is there a way to stop this?  Or is there a different function that
> > will only print what you have in the formatted string?
>
> E:\UserData\Wulfraed\My Documents>python
> ActivePython 2.7.2.5 (ActiveState Software Inc.) based on
> Python 2.7.2 (default, Jun 24 2011, 12:21:10) [MSC v.1500 32 bit
> (Intel)] on win32
> Type "help", "copyright", "credits" or "license" for more information.
>
> >>> import sys
> >>> print "1",;sys.stdout.softspace=0;print "2"
> 12
>
> >>> sys.stdout.write("1");sys.stdout.write("2");print
> 12
>
>         In Python 2.x, the equivalent of fprint/fprintf is NOT print but
> sys.stdout.write/file_object.write
>
>         "print" is just a convenience function that is designed to translate
> its arguments into a textual representation, and then drop it to the
> screen. Part of the convenience is to separate output items by a space
> and to emit a newline at the end.
>
>         .write(), OTOH, does no formatting -- not even new lines. You have
> to provide all conversion to text, and line endings.

Thanks.  I am starting to get it.

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