possibly broken starfield animation

gistfile1.py

#!/usr/bin/python2.6
# -*- coding: utf-8 -*-
# from: https://lorenzod8n.wordpress.com/2007/05/25/pygame-tutorial-1-getting-started/
import pygame
import pdb
from random import randrange, choice

x = y = 0

running = 1
MAX_STARS = 30
LAYERS = "near", "mid", "far"
BGCOLOR = 0, 0, 0
SCREEN_WIDTH = 900
SCREEN_HEIGHT = 500
screen = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT))
LEVELS = {
    "foo" :  "bar"# will need to move this back, just a placehoolder for now
    }


class Star:
    def __init__(self, **options):
        self.xcoord = options.get("xcoord", randrange(0, screen.get_width() - 1))
        self.ycoord = options.get("ycoord", randrange(0, screen.get_height() - 1))
        self.coords = (self.xcoord, self.ycoord)
        self.distance = options.get("distance", "far")
        if self.distance == "near":
            self.shade = randrange(255-30, 255)
            self.char = choice([".",  "'", ".",u"·" ])
            # "█" ASCII 219
            self.speed = 3
            self.color = self.shade, self.shade, self.shade # XXX TODO figure out a better way to do this
        elif self.distance == "mid":
            self.shade = randrange(190-15, 190+15)
            self.char = choice([ "!", ".", "'", "|", "*", "_", "'", ".", "'", "|", "*", "_", "'", u"†", "0"])
            self.speed = 2
            self.color = self.shade, self.shade, self.shade
        elif self.distance == "far":
            self.shade = randrange(100-15, 100+15)
            self.char = choice(["_","-",".","'",".","'",".","'", "__", u"‡"])
            self.speed = 1
            self.color = self.shade, self.shade, self.shade

    def getx(self):
        return self.xcoord

    def gety(self):
        return self.ycoord

    def draw(self):
        self.font = pygame.font.Font(None, 12)
        self.text = self.font.render(self.char, 1, self.color)
        screen.blit(self.text, self.coords)

    def check_collisions(self):
        "Check if bottom"
        if self.ycoord >= screen.get_height():
            w.starfield.stars.remove(self)
            star = Star(xcoord = randrange(0, screen.get_width() - 1),
                        ycoord = 0,
                        distance = choice(LAYERS))
            w.starfield.stars.append(star)

    def move(self):
        self.ycoord += self.speed
        self.coords = self.xcoord, self.ycoord
        self.check_collisions()
        

    def update(self):
        self.move()

class LoadLevel:
    def __init__(self, key):
        self.level = LEVELS[key]

    def draw(self):
        print self.level
        
class Starfield:
    def __init__(self):
        self.max_stars = MAX_STARS
        self.stars = []
        for i in range(self.max_stars):
            star = Star(xcoord = randrange(0, screen.get_width() - 1),
                        ycoord = randrange(0, screen.get_height() - 1),
                        distance = choice(LAYERS))
            self.stars.append(star)
    
class Crosshairs:
    "Cross hairs that follow the mouse and pulse blue"
    def __init__(self):
        self.blueval = 215
        self.bluedir = -1.8
        self.xcoord = 0
        self.ycoord = 0

    def draw(self, **options):
        self.xcoord = options.get("xcoord", self.xcoord)
        self.ycoord = options.get("ycoord", self.ycoord)
        pygame.draw.line(screen, (0, 0, self.blueval), (self.xcoord,0), (self.xcoord,screen.get_height() - 1))
        pygame.draw.line(screen, (0, 0, self.blueval), (0, self.ycoord), (screen.get_width() - 1, self.ycoord))
        self.blueval += self.bluedir
        if self.blueval >= 223 or self.blueval < 32: self.bluedir *= -1

    def update(self, **options):
        self.xcoord = options.get("xcoord", self.xcoord)
        self.ycoord = options.get("ycoord", self.ycoord)
        
        
class World():
    def __init__(self):
        self.cross = Crosshairs()
        self.starfield = Starfield()
#        self.curlevel = LoadLevel("foo")

    def draw(self):
        screen.fill(BGCOLOR)
        for star in self.starfield.stars:
            star.draw()
#        self.curlevel.draw()
        self.cross.draw()
        pygame.display.flip()

    def updateObjects(self):
        for star in self.starfield.stars:
            star.update()



#################
## MAIN GAME LOOP
#################
    def MainLoop(self):
        running = 1
        clock = pygame.time.Clock()

        clock.tick(30)              # 30 fps

        while running:
            self.event = pygame.event.poll()
            if self.event.type == pygame.QUIT:
                running = 0
            elif self.event.type == pygame.MOUSEMOTION:
                x, y = self.event.pos
                self.cross.update(xcoord = x,ycoord = y)
            self.updateObjects()
            self.draw()


if __name__ == "__main__":
    pygame.font.init()
    w = World()
    w.MainLoop()