It's just a simple set of python programs that interact with an arduino and a twitter bot.
First, you must create a twitter application. For that, check here : https://developer.twitter.com/en.
You must install pySerial and Tweepy packages too.
https://pythonhosted.org/pyserial/
In this application, an Arduino detects when a button is pushed and send a message. A python script recovers this message via a serial communication between the Arduino and a PC. Then, the python script is connected to a bot that tweet a message on twitter.
You can find my personnal twitter bot at https://twitter.com/BotKrounet to watch my fascinating "wanderings" :).