Permanently add a directory to PYTHONPATH?

Question

Whenever I use sys.path.append, the new directory will be added. However, once I close python, the list will revert to the previous (default?) values. How do I

Answer 1

In case anyone is still confused - if you are on a Mac, do the following:

1. Open up Terminal
2. Type open .bash_profile
3. In the text file that pops up, add this line at the end: export PYTHONPATH=$PYTHONPATH:foo/bar
4. Save the file, restart the Terminal, and you're done