You are going to take a short, working micro:bit Python program that is hard to read and turn it into one anyone could follow. You will rename its unclear variables, add a comment that says what it does, and split a tricky line into clear steps. Same behaviour, far clearer code.
Documentation is anything in a program that helps a human understand it. Two things do most of the work: clear names (a variable called score beats one called x) and comments, lines starting with # that Python ignores but people read. Good documentation does not change what a program does. It changes who can read it.
Go to python.microbit.org. Clear whatever is there and type the program below exactly. It counts button-A presses and scrolls the count. Read it first: can you tell what a, b and c are for? Click Send to micro:bit or run the simulator to prove it works.
from microbit import *
a = 0
b = 0
while True:
if button_a.is_pressed():
a = a + 1
display.scroll(a)
sleep(300)
if button_b.is_pressed():
display.scroll(a)
The name a tells you nothing. It is a count of presses, so call it presses. The variable b is never used, so delete it. Change every a to presses.
Your program should now read like the one below. Run it: it behaves exactly the same, but you can read it now.
from microbit import *
presses = 0
while True:
if button_a.is_pressed():
presses = presses + 1
display.scroll(presses)
sleep(300)
if button_b.is_pressed():
display.scroll(presses)
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