[GRASS-dev] PYTHONPATH question

[Glynn Clements]

William Kyngesburye wrote:

> > Given that the two versions are almost identical (2.5.1 vs 2.5.2), I
> > suggest setting PYTHONPATH to contain both modules' site-packages
> > directories, and nothing else.
> 
> Or make sure the correct python is running.
>
> They are similar versions, but compiled differently - one (2.5.1)  
> for OSX Leopard, the other (2.5.2) for Tiger and also-works-on- 
> Leopard.  The Mac Python list would have a better idea if this a  
> workable solution, or crazy.

Right. Python code isn't likely to care about the specific version,
but binary extensions might.

Michael Barton wrote:

> The important thing is that additional libraries like wxpython and  
> matplotlib get installed for the default version, whatever that is. We  
> want to make sure that a script is running the same python that you  
> get when you type "python" from the command line. If you *want* to run  
> it through a different python, you should just be able to use: [path  
> to desired python] myscript.py.
> 
> So what is the best way to make sure that the 'default' python is used  
> in a script?

If by "default", you mean "first in $PATH", then use the /usr/bin/env
trick.

Of course, there's no guarantee that $PATH will be the same in all
contexts. E.g. if you modify PATH in ~/.bash_profile, you may get a
different result when running a script from a terminal compared to
running the same script from a GUI application.

If you want to guarantee consistency above all else, use
#!/usr/bin/python in the script. But then we would need to process
such scripts during installation (e.g. MSys doesn't have
/usr/bin/python, and it doesn't have symlinks so you can't just make
/usr/bin/python a symlink to the actual program).

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