Create pir-sensor

[jaydevs]

Python Script for Sense movement using PIR motion sensor connected to raspberry pi GPIO pin 21.

[odyslam]

Actually I was thinking about integrating a pir sensor, sweet!
The thing is that this loop will freeze everything else, as the script will wait for the loop to end. What you do is called polling, meaning that you check the gpio x times/sec in order to see if the state changes.
In that case you can use the webiopi default gpio functions(no need to import rpi.gpio) and the threading.Timer() method in order to poll every x seconds and not constantly, so as the rest script can run.

Also you can use gpio interupts (more delicate solution) by importing an external library as you can read here