Here is a Python example demonstrating the control of the Super4 USB Relay module on the Raspberry Pi  20-Sep-2015

First, make sure the necessary drivers and tools are installed.
In a console type:

sudo apt-get install libftdi-dev
sudo apt-get install python-pip
sudo pip install pylibftdi
to edit

sudo python -m pylibftdi.examples.list_devicest

To find the name of a connected relay module, type:
Super4 Relay Module on Raspberry Pi