How can I get rid of the line following the sprites?

[Houston11]

So I've been following along with a tutorial I found online, basically this code allows me to spawn in sprites and have them move across the screen. I'm trying to figure out how to remove the lines following the sprites, is there a way to do so?

import pygame,random
 
 
class Player(pygame.sprite.Sprite):
    def __init__(self, *groups):
        super(Player, self).__init__(*groups)
        self.image = pygame.image.load('images/zombie.png')
        self.rect = pygame.rect.Rect((screen_width, (random.randrange(0,screen_height))), self.image.get_size())
        self.dx = -3
        self.pos = random.randrange(0,screen_height)
       
    def update(self):
       self.rect.centerx += self.dx
 
       if self.rect.right < 0:
           self.kill()
 
       
 
class Game(object):
    def main(self, screen):
        clock = pygame.time.Clock()
 
        sprites = pygame.sprite.Group()
        self.player = Player(sprites)
 
        while 1:
            clock.tick(40)
            numberAlien = 5

            for event in pygame.event.get():
                if event.type == pygame.QUIT:
                    return
                if event.type == pygame.KEYDOWN and event.key == pygame.K_ESCAPE:
                    return


                sprites.update()
                sprites.draw(screen)


                drone = Player()
                if sprites.__len__() < numberAlien:
                    self.y = random.randrange(0,screen_height)
                    sprites.add(drone)

                pygame.display.flip()

if __name__ == '__main__':
   pygame.init()
   screen_width = 700
   screen_height = 500
   screen = pygame.display.set_mode((screen_width, screen_height))
   Game().main(screen)

[Mekire]

Two main problems.  You aren't clearing the screen (this is causing the "lines") and you are updating and drawing in the event loop.

Here is a quick rough fix:

Hide/Show

import pygame as pg
import random


BACKGROUND_COLOR = pg.Color("darkslategray")

  
class Player(pg.sprite.Sprite):
    def __init__(self, *groups):
        super(Player, self).__init__(*groups)
        ##self.image = pg.image.load('images/zombie.png')
        self.image = pg.Surface((15,15)).convert()
        self.image.fill(pg.Color("red")) 
        self.rect = pg.rect.Rect((screen_width, (random.randrange(0,screen_height))), self.image.get_size())
        self.dx = -3
        self.pos = random.randrange(0,screen_height)
        
    def update(self):
       self.rect.centerx += self.dx
  
       if self.rect.right < 0:
           self.kill()
  
        
  
class Game(object):
    def __init__(self):
        self.done = False

    
    def main(self, screen):
        clock = pg.time.Clock()
        sprites = pg.sprite.Group()
        self.player = Player(sprites)
  
        while not self.done:
            numberAlien = 5
 
            for event in pg.event.get():
                if event.type == pg.QUIT:
                    self.done = True
                if event.type == pg.KEYDOWN and event.key == pg.K_ESCAPE:
                    self.done = True
 
 
            sprites.update()
            screen.fill(BACKGROUND_COLOR)
            sprites.draw(screen)

            drone = Player()
            if sprites.__len__() < numberAlien:
                self.y = random.randrange(0,screen_height)
                sprites.add(drone)

            pg.display.flip()
            clock.tick(60)
 
if __name__ == '__main__':
   pg.init()
   screen_width = 700
   screen_height = 500
   screen = pg.display.set_mode((screen_width, screen_height))
   Game().main(screen)

Also please look here for an example of a base pygame program:
Pygame Template