Pygame images move with rotation

Question

I am still having problems with rotation (see my previous question) so to solve them i took the problem out of the context of my game, to see if i could get it to rotate without the confusion of everything else i was trying to do. The problem I have now is that the image rotates, but it also flies off screen at the same time. I do not have any move commands, it is only supposed to rotate in place. why is this happening?

here is my code:

import pygame
import sys

pygame.init()

size = width , height = 400 , 400

screen = pygame.display.set_mode(size)

car = pygame.image.load("Car3.png").convert()
carRect = car.get_rect()
carRect = carRect.move(200 , 200)

running = True

while running:

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
           running = False

    car = pygame.transform.rotozoom(car ,30  , 1)

    screen.blit(car , carRect)
    pygame.display.flip()

pygame.quit()
sys.exit()

note: the reason i am using rotozoom is that i read that problems can arise from the image automatically resizing when it is rotated.

Answer 1

What are you planning to achieve by using these two lines here?

carRect = car.get_rect()
carRect = carRect.move(200 , 200)

Why do you call the Rect.move function here?

Your problem is probably, that the blit is done with the top left corner. I don't know the measurements of your image, but could it be that it's "rotating" out of the window because the top left corner shifts during the rotation process?

It's a bit late here, otherwise I'd look up the documentaion myself and give you a more elaborate answer. But till then: When rotating images, I'd go by the center of the image for placing it, and not by its top left corner. Can be done either way, I find it easier using the center.