For more information, see http://ok100.github.io/lyvi/
You can install the python dependencies by issuing:
$ sudo pip install -r pip_requirements.txt --use-mirrors
This will also be done for you when issuing the setup.py script.
There are other dependencies that need to be installed separately though:
For MPRIS support these dependencies are needed:
python-dbus
python-gobject
On OS X homebrew:
brew install dbus
brew install pygobject3
Chances are that all these are available by your package manager.