[PyGame] how to make objects move at a precise amount of time?

[Zhaleh]

I'm not sure if I understand you well but this is how I changed my code. Would you look at that and tell me if this is what you meant? The values in the list 'speed' are going to give me the time intervals I want between collistions: 500, 500, 1000, 750, 250 ms

import pygame 
pygame.init()
screen=pygame.display.set_mode((1000,1000)) 

pygame.display.set_caption('visual rhythm')
icon=pygame.image.load("song.png")
pygame.display.set_icon(icon)

playerImg=pygame.image.load('spaceship.png')
playerX=370
playerY=400
def player(x,y):
    screen.blit(playerImg,(int(x),int(y)))

speed=[4000, -2000 , 2000 , -1000 , 1333 , -4000]
count=0
count2=0
clock=pygame.time.Clock()
while count2<len(speed):
    screen.fill((0,255,0))
    milli=clock.tick()
    seconds=milli/1000.0
    dm=seconds*speed[count]
    playerY+=dm
    player(playerX,playerY)
    pygame.display.update()
    if playerY>=946 or playerY<1:
        count+=1
        count2+=1