This robotic lawnmower will do laps on your floor and maybe whack small things that it runs over with its high speed spinning blade underneath.
At the end of each pass, the mower uses a hidden trick to turn around, similar to the way a human turns a real lawnmower, except there's nobody driving this one!
These four program all do the same thing. The three Word Blocks versions show how variables and then My Blocks can be added to a program to make it easier to read or modify. The Python version takes the Lawnmower 3 program, re-writes it in Python, and then defines a couple more functions (the Python equivalent of a My Block) to make it easier to read and modify.