[Tutor] commands module (Forwarded back to list)

Evert Rol evert.rol at gmail.com
Fri Dec 7 04:09:44 CET 2007

> So, I tried setting COLUMNS equal to 500 (arbitrarily large) prior to
> going into python.  It seems to change back to 158 automatically  
> however.
> For example, when I go into python, import commands, and execute
> commands.getoutput('set') I find that COLUMNS is back to 158.  So, I
> think my problem is that I don't know how to alter the set variable so
> that it will stick long enough for the "ps ax" command to execute  
> properly.

I've had this problem before (setting/altering shell variables when  
executing a command from Python, albeit using os.system() instead).  
What I'd use is:
commands.getoutput('COLUMNS=500 ps ax')
or similar. In your case, you've been able to solve in another way  
(and better, since environment independent, though still shell/ps- 
variant dependent), but sometimes one may need to set/change shell  
variables, like paths to dynamic libraries. The above should work  
(for more variables, just specify them all before the actual command,  
whitespace separated).

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