virtualenvwrapper has broken dependencies right now on macOS, so install like this:
sudo pip install pbr
sudo pip install --no-deps stevedore
sudo pip install --no-deps virtualenvwrapper
So that the commands mkvirtualenv and workon stay in your shell, you're going to want to do this (if you use zsh or another shell, change the filename here):
echo "source /usr/local/bin/virturalenvwrapper.sh" >> ~/.bashrc
source ~/.bashrc
Make your first virtualenv
mkvirtualenv test
This creates and activates the 'test' virtualenv.
When you're done, you can:
deactivate
Just like any other virtualenv, to get out of it.
Later when you want to work on it, you can
workon test