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_
I know this has been answered for some time, but there are some points that some may want to know about using PYTHONPATH instead of PATH in their environment variable. I have outlined an explanation of running python scripts with cronjobs that deals with the modified environment in a different way (found here). Thought it would be of some good for those who, like me, needed just a bit more than this answer provided.