Why is Pygame waiting for sprites to load before creating the window?

I've been trying to create a sprite creator, but I notice that the pygame window doesn't load until all of those sprites have been created, and I wanted to know 2 things:

1. Why it only loads the screen when all of these sprites have been created
2. How could I fix this without changing too much

code:

#!/usr/bin/env python3
import random
import pygame
import time

display_width = 1280
display_height = 720
rotation = random.randint(0, 359)
size = random.random()
pic = pygame.image.load('assets/meteor.png')
pygame.init()
clock = pygame.time.Clock()
running = True


class Meteor(pygame.sprite.Sprite):
    def __init__(self, x=0, y=0):
        pygame.sprite.Sprite.__init__(self)

        self.rotation = random.randint(0, 359)
        self.size = random.randint(1, 2)
        self.image = pic
        self.image = pygame.transform.rotozoom(self.image, self.rotation, self.size)

        self.rect = self.image.get_rect()
        self.rect.center = (x, y)


all_meteors = pygame.sprite.Group()

# completely random spawn
for i in range(5):
    new_x = random.randrange(0, display_width)
    new_y = random.randrange(0, display_height)
    all_meteors.add(Meteor(new_x, new_y))
    time.sleep(2) # this*5 = time for screen to show up

main:

import pygame
import meteors
pygame.init()
while True:
    meteors.all_meteors.update()
    meteors.all_meteors.draw(screen)
    pygame.display.update()

I do not have a clue on why it prioritizes creating the sprites before creating the pygame window, and it prevents me from creating endless amounts of meteor sprites.

Don't create the meteors before the application loop, create them with a time delay in the loop.

Use pygame.time.get_ticks() to get the current time in milliseconds and set the start time, before the main loop. Define a time interval after which a new meteorite should appear. When a meteorite spawns, calculate the time when the next meteorite must spawn:

next_meteor_time = 0
meteor_interval = 2000 # 2000 milliseconds == 2 sceonds

while ready:
    clock.tick(60)  # FPS, Everything happens per frame
    for event in pygame.event.get():
        # [...]

    # [...]

    current_time = pygame.time.get_ticks()
    if current_time >= next_meteor_time:
         next_meteor_time += meteor_interval
         new_x = random.randrange(0, display_width)
         new_y = random.randrange(0, display_height)
         all_meteors.add(Meteor(new_x, new_y))

    # [...]


    meteors.all_meteors.update()
    meteors.all_meteors.draw(screen)
    pygame.display.update()