Python multithreading with PyGame

Question

I am using pygame and trying to setup multiprocessing where some code runs in the background.

I have pygame running from a class:

class UI:
    def __init__(self, window_size, world_size, scale = 10, fps = 60):
        self.window_size = window_size
        self.world_size = world_size
        self.scale = scale
        self.fps = fps

        pygame.init()
        self.fpsClock = pygame.time.Clock()
        self.Window = pygame.display.set_mode(window_size)
        pygame.display.set_caption('RADAR')
    
    def step(self):
         # Get inputs
        for event in pygame.event.get() :
         if event.type == QUIT :
            pygame.quit()
            sys.exit()
    
        # Processing
        # This section will be built out later
 
        # Render elements of the game
        self.Window.fill(BACKGROUND)
        pygame.display.update()
    
    def run(self):
        while True:
            self.step()

And my process that I'm trying to run is very simple:

def test():
    while True:
        print("Hello from a thread!")

In my main function I am calling:

if __name__=="__main__":

    ui = UI((700,700),(700,700))
    p = Thread(Environment.test())
    p.start()
    ui.run()

It seems to only run the thread and doesn't actually run the pyGame code. In know python isn't great for multi threading but any suggestions?