Python subprocess/Popen with a modified environment

python subprocess popen

Oren_H · Feb 9, 2010 · Viewed 201.2k times · Source

I believe that running an external command with a slightly modified environment is a very common case. That's how I tend to do it:

import subprocess, os
my_env = os.environ
my_env["PATH"] = "/usr/sbin:/sbin:" + my_env["PATH"]
subprocess.Popen(my_command, env=my_env)

I've got a gut feeling that there's a better way; does it look alright?

Answer

I think os.environ.copy() is better if you don't intend to modify the os.environ for the current process:

import subprocess, os
my_env = os.environ.copy()
my_env["PATH"] = "/usr/sbin:/sbin:" + my_env["PATH"]
subprocess.Popen(my_command, env=my_env)