[GRASS-dev] New wiki page summarising GRASS APIs

[Vaclav Petras]

On Sun, Feb 1, 2015 at 2:26 PM, Moritz Lennert <mlennert at club.worldonline.be
> wrote:

> On 01/02/15 12:29, Glynn Clements wrote:
>
>>
>> Pietro wrote:
>>
>>  {{{
>>> import os
>>> os.system('g.region rast=elevation')
>>> }}}
>>>
>>> and not subprocess:
>>>
>>> {{{
>>> import subprocess
>>> subprocess.call('g.region rast=elevation', shell=True)
>>>
>>> # or
>>>
>>> subprocess.Popen('g.region rast=elevation', shell=True)
>>> }}}
>>>
>>> Concerning the pygrass Module API, may be we can use the shortcut
>>> version:
>>>
>>
>> Using subprocess.call() with shell=True is no better than using
>> os.system(). Both should be avoided at all costs.
>>
>> The grass.script module provides a number of convenience functions
>> which use grass.script.make_command() to generate the command's
>> argument list from the function's argument list. Also, they use a
>> version of subprocess.Popen() which has been wrapped to deal with some
>> of Windows' idiosyncrasies.
>>
>>
>
> Just to be clear: the example on this wiki page shows just that it is
> possible to call any GRASS module from any language that allows system
> calls. It then goes on to introduce the scripting API to show how that
> eases things on the script writer since she doesn't have to deal with any
> idiosyncrasies.
>
> But if this causes too much opposition I can take it out or at least put a
> big warning of likes of "Don't use this ! Example code only."
>
>
I suggest to use Bash example instead of Python one because this is how it
is actually (also) used.

If some warning is needed, it probably applies to all, Bash, C system calls
and Perl too.

Do you consider a section for 3rd party APIs? Particularly I'm asking about
spgrass in R (the same philosophy as grass.script for Python) and QGIS
Processing (wrapper, limited functionality?, different philosophy).


> Moritz
>
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