There were two problems I ran into which weren't included in the tutorial I was reading here.
The first was the addition of:
os.environ['PYTHON_EGG_CACHE'] = '/path/to/.python-eggs/'
to the application start script. Since I had not had this specified the framework kept trying to write to "/root/.python-eggs", and obviously it didn't have permissions to write to this directory.
The second problem was my mistake. In the .htaccess file we need to put the following lines:
PythonOption cherrysetup Project_Start_Script_Name::mp_setup
I had put in the full name of the script which was gs_start.py in place of Project_Start_Script_Name, which was giving the cryptic error "could not import py". To solve this, simply put gs_start::mp_setup without the .py.