Un Nu Python Pygame Multi-touch

import pygame
from pygame import Vector2, Rect
from pygame.locals import *

class control:
    def __init__(s, px, py):
        global PDR
        pos = Vector2(px * PDR.w, py * PDR.h)
        s.r = Rect(pos - (100, 100), (200, 200))

pygame.init()
PDS = pygame.display.set_mode()
PDR = PDS.get_rect()

BLACK = (0, 0, 0)
WHITE = (255, 255, 255)

controls = {}

while True:
    events = pygame.event.get()
    for e in events:
        if e.type == FINGERDOWN:
            controls[e.finger_id] = control(e.x, e.y)
        if e.type == FINGERUP:
            del controls[e.finger_id]

    PDS.fill(BLACK)
    for fid, c in controls.items():
        pygame.draw.rect(PDS, WHITE, c.r)
    pygame.display.update()
    pygame.time.Clock().tick(60)