Re: [Gimp-web] Proposed gimp tutorial

[Stephen Kiel <snick kiel gmail com>]

Pat,

I did look into the DIR-SEPARATOR (DIR_SEPARATOR on python?) constant. 
It did not appear to be documented anywhere in the gimp docs that I 
could find with a search engine.  From an old scheme script I found 
posted I was able to find the following:

The DIR-SEPARATOR constant appears to be just a "/" on platforms where 
the OS is Linux and "\" on platforms where the OS is Windows. The 
following is pasted from a Script-Fu Console and a Python-Fu Console 
(Linux).

**** Script-Fu Console*

Welcome to TinyScheme
Copyright (c) Dimitrios Souflis
Script-Fu Console - Interactive Scheme Development

> (string-append "Yaba" DIR-SEPARATOR "Daba" DIR-SEPARATOR "Doo")
"Yaba/Daba/Doo"


**** PYTHON CONSOLE*

GIMP 2.8.10 Python Console
Python 2.7.5 (default, Feb 11 2014, 10:29:30)
[GCC 4.8.2 20131212 (Red Hat 4.8.2-7)]
>>> import os
>>> print os.sep
/
>>> from gimpfu import *
>>> print DIR_SEPARATOR
Traceback (most recent call last):
  File "<input>", line 1, in <module>
NameError: name 'DIR_SEPARATOR' is not defined
>>> print DIR-SEPARATOR
Traceback (most recent call last):
  File "<input>", line 1, in <module>
NameError: name 'DIR' is not defined
>>> if DIR_SEPARATOR == "/":
...     print "YES"
...
Traceback (most recent call last):
  File "<input>", line 1, in <module>
NameError: name 'DIR_SEPARATOR' is not defined
>>>

In python, os.sep does the same job that we would expect from
what we see in the scheme example except it has the following
advantages:

1. It is documented
2. It has a wide user base, so it should be robust
3. It works in any python shell, so you can debug programs using wide
   range of tools.
4. It works.

It seems like os.sep would be a much better design choice **IF** we 
actually needed to determine a platform portable directory separator.  
As far as I can tell, we don't.

In the code I use python functions that take care of the separator.
e.g.
srcFile = os.path.join(srcPath, srcFile)
Python sticks in the right separator for the host OS.

From my point of view, it seems like using the DIR_SEPARATOR and 
manually concatenating strings would make the code clumsy. I did not see 
anywhere where knowing what the separator character was would be
an advantage.

I wanted to keep the focus of the tutorial on Automation and not get 
sidetracked too much on design and architecture.  It is worth while to 
note that if you can design a block of code (like autoBase.py) that does 
not use the gimpfu library, you can run it on any python shell and use 
any debugging tools at your disposal.  This is a real advantage over 
debugging in Gimp.  So I view using a gimp constant instead of a python 
library function (os.sep) as kind of a mistake.

Please let me know if I missed something.

Stephen

On 2/20/2014 1:03 PM, Pat David wrote:
> Stephen,
>
> Just a couple of notes.  There are some concerns about the 
> introduction of the term "macro" in the tutorial and the sense with 
> which it's used.
>
> Also, saul has asked me to relay to you: "have him look into the 
> DIR-SEPARATOR constant. Using it would obviate about half of his code."
>
> If you can take a look at DIR-SEPARATOR to see if perhaps it can help 
> streamline things a bit, that would be great.  I'm also hoping others 
> might be able to chime in with other suggestions as well.
>
> There is a consideration of moving this to the wiki as opposed to wgo 
> as well.
>
>
>
> On Thu, Feb 20, 2014 at 1:37 PM, Pat David <patdavid gmail com 
> <mailto:patdavid gmail com>> wrote:
>
>     Stephen,
>
>     I've converted the tutorial to HTML to fit the website.  I've
>     pushed it up along with the assets, and am now just waiting on
>     someone to poke wgo for it to show up.  Keep an eye on the
>     tutorials page.
>
>
>     On Thu, Feb 20, 2014 at 1:29 PM, Stephen Kiel
>     <snick kiel gmail com <mailto:snick kiel gmail com>> wrote:
>
>         Pat,
>         Thanks.  Let me know if there are any issues.
>         Stephen
>
>         On Feb 20, 2014 7:27 AM, "Pat David" <patdavid gmail com
>         <mailto:patdavid gmail com>> wrote:
>
>             Hi Stephen!
>
>             You can just leave it as an ODT file.  I'll make the
>             stylistic changes required to fit the website HTML.
>
>             Give me a little time and I'll make the conversion and get
>             it up to test.
>
>             Thanks for the contribution!
>
>             -- 
>             pat david
>             http://blog.patdavid.net
>
>
>
>
>     -- 
>     pat david
>     http://blog.patdavid.net
>
>
>
>
> --
> pat david
> http://blog.patdavid.net

--
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