Setting up a virtualenv with Node.js

The following steps will: create a virtualenv, named myenv, in the current directory; activate the virtualenv; and install npm inside the virtualenv using nodeenv:

python3 -m venv myenv          # For Python 2: python2 -m virtualenv myenv
source myenv/bin/activate
pip install nodeenv
nodeenv -p

With this environment active, you can now install nbdime and its dependencies using pip.

For example with Python 3.5, the steps with output are:

$ python3 -m venv myenv
$ source myenv/bin/activate
(myenv) $ pip install nodeenv
Collecting nodeenv
  Downloading nodeenv-1.0.0.tar.gz
Installing collected packages: nodeenv
  Running setup.py install for nodeenv ... done
Successfully installed nodeenv-1.0.0
(myenv) $ nodeenv -p
 * Install prebuilt node (7.2.0) ..... done.
 * Appending data to /Users/username/myenv/bin/activate
(myenv) $