connerting asteroids.py

import pgzrun
from random import randint
from time import time
WIDTH=800
HEIGHT=600
SATELLITES=[]
lines=[]
next_satellite=0

start_time=0
total_time=0
number_of_satellites=25
end_time=0

def create_satellites():
    global start_time
    for i in range(0,number_of_satellites):
       satellite =Actor("new asteroid")
       satellite.pos=randint(40,WIDTH-40), randint(40,HEIGHT-40)
       SATELLITES.append(satellite)
    start_time=time()
def draw():
    global total_time
    screen.blit('background',(0,0))
    number=1
    for satellite in SATELLITES:
        screen.draw.text(str(number),(satellite.pos[0],satellite.pos[1]+20))
        satellite.draw()
        number=number+1
    for line in lines:
        screen.draw.line(line[0],line[1],(255,255,255))
    if next_satellite<number_of_satellites:
        total_time=time()-start_time
        screen.draw.text(str(round(total_time,1)),(10,10),fontsize=30)
    else:
        screen.draw.text(str(round(total_time,1)),(10,10),fontsize=30)
def update():
    pass
def on_mouse_down(pos):
    global next_satellite,lines
    if next_satellite<number_of_satellites:
        if SATELLITES[next_satellite].collidepoint(pos):
            if next_satellite:
                lines.append((SATELLITES[next_satellite-1].pos,SATELLITES[next_satellite].pos))
            next_satellite=next_satellite+1
        else:
            lines=[]
            next_satellite=0
create_satellites()
pgzrun.go()