python subprocess set shell var. and then run command - how?

Question

I need to do this:

$ export PYRO_HMAC_KEY=123
$ python -m Pyro4.naming

So, i found that the second one is possible to do with

subprocess.Popen(['python','-m','Pyro4.naming'])

but how export shell variable before that?

Answer 1

To update the existing environment...

import os, subprocess

d = dict(os.environ)   # Make a copy of the current environment
d['PYRO_HMAC_KEY'] = '123'
subprocess.Popen(['python', '-m', 'Pyro4.naming'], env=d)