How to keep direction of sprites?

Im trying to make a simulation.

My rabbit's are supposed to be moving around randomly, but i would like them to keep moving the same direction for longer, hence, why i use the if randomnum == 1, to only change the direction 1/10 times.

But when i run the code the rabbits seem to change direction every move. What am i doing wrong?

rabbit-constructor

class Rabbit(pygame.sprite.Sprite): def init(self,x,y): super().init()

    self.image = pygame.Surface([10,10])
    self.image.fill(BLUE)

    self.rect = self.image.get_rect()
    self.rect.x = x
    self.rect.y = y
    self.xchange = 0
    self.ychange = 0
    self.hp = 100

rabbit-mover

for rabbit in rabbits:
    randomnum = random.randint(1,10)
    if randomnum == 1:
        xdir = random.randint(-5,5)
        ydir = random.randint(-5,5)
        rabbit.xchange = xdir
        rabbit.ychange = ydir
    else:
        continue
    if rabbit.rect.x+xdir > 10 and rabbit.rect.x+xdir < 390 and rabbit.rect.y+ydir > 10 and rabbit.rect.y+ydir < 390:
            rabbit.rect.x += rabbit.xchange
            rabbit.rect.y += rabbit.ychange
    else:
        continue