Help with circle and motion

[wigigx]

Hi there.
I am new here, so I say hello to all of you and thanks in advance.

I am a newbie trying to get my hands on Python.
I have some visual problems (myopia and squint, so excuse my writing (maybe I miss a few characters that I do not really see).

Well, I want to help myself by creating a small program to do this:

I need to draw a circle, only the circumference, no painted inside.

Then a need a big dot circling the circle (do you remember the old movies where a sonar tries to get something? some like that, BUT something rounding the circle), not the inner but the outside.

The idea is to get my eyes to follow the dot rounding the circle in order to get my muscles relaxed.

No big deal, BUT I do not have a clue how to start.

SO I split the problem and try to get an approach with some Pseudocode:

Init python
clear screen
get the dimension of the screen
draw a circle as big as the screen
put a dot in the circumference of the circle
start to rotate the dot following the circle from right to left
get a button to reverse from left to right
get a button to stop the exercise and exit gracefully

end


Well, I ask help with some ideas, maybe some libraries or functions, I do not ask the whole code written, I'd like to make it on my own, but some scratch to start from.

Thanks in advance!

my code here