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From: Laura Creighton <lac@openend.se>
Subject: Re: Modify environment variable for subprocess
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Comments: In-reply-to loial <jldunn2000@gmail.com> message dated "Wed, 23 Sep 2015 02:51:53 -0700."
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Date: Wed, 23 Sep 2015 12:37:23 +0200
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In a message of Wed, 23 Sep 2015 02:51:53 -0700, loial writes:
>I need to modify the LIBPATH environment variable when running a process =
via subprocess, but otherwise retain the existing environment.
>
>Whats the best way to do that?

import subprocess, os
my_env =3D os.environ  # if your program should be able to modify the curr=
ent env
# otherwise
my_env =3D os.environ.copy() # if it shouldn't

# if you just want to add something to the existing LIBPATH
my_env["LIBPATH"] =3D "/where/I/want/to/look/first:" + my_env["LIBPATH"]
# otherwise
my_env["LIBPATH"] =3D "/what/I/want"

subprocess.Popen(my_program, env=3Dmy_env)

Setting os.environ leaks memory under Mac OS and FreeBSD.
I am not sure if this means that if  you do this a gazillion times
on a Mac you will have a problem.

Laura