pygame update(rect) problem (macOS) about pygame HOT 5 OPEN

Thank you. I believe I already understand how to draw a rectangle on a black background, as you describe. However, my program is TRYING TO UNDERSTAND how update(rect) works, and it appears to me (a non-expert) not to be working correctly.

My understanding is that, by updating only the rect area, the displaySurf.fill(white) will only be "executed" (or be effective or applicable) within the rect area being updated. Since that rect area is also being updated by the 2-color rectangle (which comes after (later than) the fill), it presumably should allow the fill to execute only in the rect area, so the entire background (outside the rect area) should remain black.

This is toy code with a purpose. I am new to pygame. (I am trying to use it to make a rather sophisticated 2D drawing program.) So I may not understand how update(rect) is supposed to work. So, yes, there may be a bug in my thinking rather than a bug in the code, but I would certainly like to know which it is.

from pygame.

The issue is likely due to the fact that the pygame.display.update(rect) call updates the entire display surface and not just the specified rectangle. for updating the rectangle area you have to say pygame.display.update() code.
and sorry for my wrong answer i thought you just to create a white background application . if this will help you then comment if not then sorry again plz.
and you can read pygame documentation for getting the detailed explanation over their functions

from pygame.

NOTE: Actual code has correct indentation and runs.

from pygame.

you may need to wrap your code like this:

your code

from pygame.

Hi , @sabrawer
This is not looking like a bug here you done a slight mistake that is only updated the rectangle by 'pygame.display.update(rect)' instead of this you can go for 'pygame.display.update()' for make the background full white and for black background just remove 'displaySurf.fill((255,255,255))' from the code.
I hope this will help you. ☺️

from pygame.