This is a simple Python Code for Raspberry Pi which allows User to "Shutdown" and "Reboot" their Pi using a physical button.
Installation process:
1.Move the PiButton.py to /usr/local/bin/
mv PiButton.py /usr/local/bin/
2.Move the PiButton.sh to /etc/init.d/
mv PiButton.sh /etc/init.d/
3.Add the following line to the /etc/rc.local to run the code at Boot.
sudo /etc/init.d/PiButton.sh start

Connect a Button between GPIO Pin 17 and Ground.

Pressing and holding the button for 3 Seconds reboots Raspberry Pi.
Short press shutdowns Raspberry Pi after 3 Seconds.