How to read it:
Look at it as you look at a clock now: hours, minutes and seconds.
Each column represents a number. You find out that number by adding the rows which are bright.
Each row represents a value. From bottom to top, those values are one, two, four and eight.
When I write this statement, it is 12:23 PM.
In the first column, the bottom row would be bright. In the second column, the second row would be bright. That’s your number 12 for the hours.
In the third column, the second row would be bright. In the fourth column, the first and second row (one plus two equals three) would be bright. That’s your number 23 for the minutes.
The fifth and sixth column represent the seconds. Watching that is a good way to quickly understand how BCD works.
“Wait!”, you say. “How did you make a window screen saver using python and pygame?”
Could you post a little bit about how you turned a Python program into a Windows screensaver?
All set. You should be able to follow my instructions. Let me know if you need anything else cleared up.