How do install node.js and bower in virtualenv

I'm trying to see how django-scheduler works and so want to install it in a virtualenv.

Having unzipped the files into the relevant directory, here's what I've done:

virtualenv env
env/bin/pip install -r requirements.txt
export DJANGO_SETTINGS_MODULE=project_sample.settings
python manage.py bower install

At this point I get the error:

/usr/bin/env: ‘node’: No such file or directory

Given that didn't work I've tried following this blog and did

env/bin/pip install nodeenv
env/bin/pip install django-bower
env/bin/nodeenv --prebuilt -p

I get the same result. How do I install within a virtualenv?

via HenryM