Python Pygame Center Camera

import sys, time, random
import pygame

class c:
    def __init__(s, x, y, r):
        s.rect = pygame.Rect(x - r // 2, y - r // 2, r * 2, r * 2)
        s.rad = r

    def draw(s):
        global PDS, VP

        if s.rect.colliderect(VP):
            #print(s.rect.centerx)
            pygame.draw.circle(PDS, (255, 255, 255), (s.rect.centerx - VP.x, s.rect.centery - VP.y), s.rad)

pygame.init()

PDR = pygame.Rect(0, 0, 1024, 720)
PDCENTER = pygame.math.Vector2(PDR.center)
PDS = pygame.display.set_mode(PDR.size)
FPS = 120

# viewport or camera
VP = pygame.Rect(0, 0, 1024, 720)

PLAYER_RADIUS = pygame.math.Vector2(20)
PLAYER = pygame.Rect(PDCENTER - PLAYER_RADIUS, PLAYER_RADIUS * 2)

# generate NPCs
circles = [c(random.randint(0, 10000), random.randint(0, 4000), random.randint(5, 20)) for i in range(100)]

while True:
    events = pygame.event.get()
    for e in events:
        if e.type == pygame.QUIT: sys.exit()

    PDS.fill((0, 0, 0))

    # default player is green
    playerColor = (0, 255, 0)
    # draw NPC
    for circle in circles:
        circle.draw()
        if circle.rect.colliderect((PLAYER.x + VP.x, PLAYER.y + VP.y), PLAYER_RADIUS * 2):
            playerColor = (255, 0, 0) # player turns red if collides with NPC

    # draw player in red
    pygame.draw.circle(PDS, playerColor, PLAYER.center, PLAYER_RADIUS[0])

    pygame.display.update()

    k = pygame.key.get_pressed()
    if k[pygame.K_RIGHT]:
        VP.move_ip(1, 0)
    if k[pygame.K_LEFT]:
        VP.move_ip(-1, 0)
    if k[pygame.K_UP]:
        VP.move_ip(0, -1)
    if k[pygame.K_DOWN]:
        VP.move_ip(0, 1)

pygame.quit()
sys.exit()