How it works...

The first line of code imports the Circuit Playground Express library. The cpx object exposes a property called button_a. This property will return True when the button is pressed, and it will return False when the button is not pressed.

The script loops forever with a 50 millisecond delay between each loop. The state of the button press is continually printed. When running this program, hold and release the push button to see the printed output change.