A quick fix:

Make the entire screen white and then draw the second screen onto the first one.
Then when you need the other screen, just refill the screen with black and then continue.
This can be achieved by putting the screens in their own separate functions.

Let me know if this helps out
I am very new to python and pygame and I'm currently making a very basic experiment with it. So far, I know how to draw an image on the screen, move it around, add a background, stuff like that. But what I have always been wondering is, how do I switch between screens in a game and how do I keep the code tidy when doing so?
Every time I try to add a new thing to my already unstable code, it takes only a few lines to break it and it becomes a confusing mess.
If for example, I want a start screen that shows the title and a "press any key to continue" kinda thing, how do I do it?
How to make multiple screens in pygame? (As in, a "menu" screen, a "main" screen, a "start" screen, etc.)