[GRASS-dev] Handling of Python scripts on MS Windows

[Glynn Clements]

Markus Metz wrote:

> >> No, there are different versions of Python 2.7, and not all work with
> >> GRASS, see e.g. ticket 2015
> >
> > Any version of Python 2.7 should be suitable for GRASS.
> 
> Not all versions of Python 2.7 are suitable for WinGRASS, see ticket #2150.

To the extent that I can make any sense of that ticket, it appears to
relate to issues caused by attempting to bundle Python.

Bundling the exact same version which is installed system-wide will
obviously hide some of the problems.

> > "Executing" a script uses the registry associations for the script's
> > extension.
> 
> WinGRASS does not set registry associations for Python scripts, nor
> does it install Python system-wide. This is because we do not want to
> modify an existing Python installation.

The registry associations are set by the Python installer. This is why
you can't reasonably bundle Python.

> > Attempting to by-pass the system's script execution mechanism (by
> > explicitly executing Python scripts via a specific interpreter) is the
> > cause of all the trouble.
> 
> I disagree. Troubles arise if the system's interpreter, e.g. Python
> installed by ArcGIS, is used instead of the python version embedded in
> WinGRASS.

Most of the troubles arise from attempting to use a mixture of a
bundled version and a system-wide installation. Which wouldn't be an
issue if people didn't attempt to bundle Python.

-- 
Glynn Clements <glynn at gclements.plus.com>