Luke James - Bullets Bullets Bullets

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

class bullet:
    def __init__(s, source, target):
        degs = Vector2().angle_to(target - source)
        s.velocity = Vector2(1, 0).rotate(degs) * 5
        s.pos = Vector2(source)
        s.dead = False

    def draw(s):
        global PDS, RED

        pygame.draw.circle(PDS, RED, s.pos, 6)

    def update(s):
        global deltatime

        s.pos += s.velocity * deltatime
        if s.pos.x < -3 or s.pos.x > PDR.w + 3 or s.pos.y < -3 or s.pos.y > PDR.h + 3:
            s.dead = True

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

pygame.init()
PDR = Rect(0, 0, 1280, 720)
PDS = pygame.display.set_mode(PDR.size)
FPS = 120

base = Vector2(PDR.center)
bullets = []

bullet_timestamp = time.time() - 0.5
deltatime_timestamp = time.time()

exit_demo = False
while not exit_demo:
    for e in pygame.event.get():
        if e.type == KEYUP and e.key == K_ESCAPE:
            exit_demo = True

    now = time.time()
    deltatime = (now - deltatime_timestamp) * FPS
    deltatime_timestamp = now

    PDS.fill(BLACK)

    for b in bullets:
        b.draw()
    pygame.draw.circle(PDS, WHITE, base, 50)
    pygame.display.update()

    deadbullets = []
    for b in bullets:
        b.update()
        if b.dead:
            deadbullets.append(b)
    for b in deadbullets:
        bullets.remove(b)

    mp = Vector2(pygame.mouse.get_pos())
    mb = pygame.mouse.get_pressed()

    if mb[0] and now - bullet_timestamp > 0.1:
        bullets.append(bullet(base, mp))
        bullet_timestamp = now

pygame.quit()