Common functions for interacting with PiFace products.

http://pifacecommon.readthedocs.org/

You can also find the documentation installed at:

/usr/share/doc/python3-pifacecommon/

Make sure you are using the lastest version of Raspbian:

$ sudo apt-get update
$ sudo apt-get upgrade

Install pifacecommon (for Python 3 and 2) with the following command:

$ sudo apt-get install python{,3}-pifacecommon

You will also need to set up automatic loading of the SPI kernel module which can be done with the lastest version of raspi-config. Run:

$ sudo raspi-config

Then navigate to Advanced Options, SPI and select yes.