I recommend to use a timer event. Use pygame.time.set_timer() to repeatedly create an event on the event queue.
Use a pygame.sprite.Group and derive Enemy from pygame.sprite.Sprite to manage multiple enemies. Note it is important to use the attributes .image and .rect in a sprite. e.g.:
class Enemy(pygame.sprite.Sprite):
asteroids = [pygame.image.load('rock0.png'), pygame.image.load('rock1.png'), pygame.image.load('rock2.png'),
pygame.image.load('rock3.png'), pygame.image.load('rock4.png')]
def __init__(self, y, width, height):
super().__init__()
self.width = width
self.height = height
self.vel = 1.5
x = random.randrange(screen_width - self.width * 2)
self.image = random.choice(self.asteroids)
self.rect = self.image.get_rect(center = (x, y))
def move(self):
self.rect.y += self.vel
enemies = pygame.sprite.Group()
my_event_id = pygame.USEREVENT + 1
pygame.time.set_timer(my_event_id, 2000) # 2000 milliseconds = 2 seconds
run = True
while run:
last = pygame.time.get_ticks()
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
elif event.type == my_event_id:
# spawn new enemy
enemies.add(Enemy(10, 64, 64))
# [...]
for e in enemies:
e.move()
# [...]
enemies.draw(win)
If you make Projectile a pygame.sprite.Sprite, then you can use and bullets a pygame.sprite.Group, then you can use pygame.sprite.spritecollide() or pygame.sprite.groupcollide() to find hits and kill the enemies. e.g.:
class Projectile(pygame.sprite.Sprite):
def __init__(self, x, y, width, height, color):
super().__init__()
self.image = pygame.Surface((width, height))
self.image.fill(color)
self.rect = self.image.get_rect(center = (x, y))
self.vel = 5
def move(self):
self.rect.y -= self.vel
bullets = pygame.sprite.Group()
def spawn_bullet():
if keys[pygame.K_SPACE]:
bullets.add(Projectile((man.x + man.width // 2), (man.y - 7), 3, 7, (255, 0, 0)))
def re_draw():
win.fill((0, 0, 0))
enemies.draw(win)
man.draw(win)
bullets.draw(win)
pygame.display.update()
while run:
# [...]
for e in enemies:
e.move()
if e.rect.y > 500:
e.kill()
for b in bullets:
b.move()
if 0 > b.rect.y or b.rect.y > 500:
b.kill()
pygame.sprite.groupcollide(bullets, enemies, True, True)
Full code:
import pygame
import random
pygame.init()
screen_width = 500
screen_height = 500
win = pygame.display.set_mode((screen_width, screen_height))
walk_left = [pygame.image.load('sprite_5.png'), pygame.image.load('sprite_6.png')]
walk_right = [pygame.image.load('sprite_3.png'), pygame.image.load('sprite_4.png')]
standing = [pygame.image.load('sprite_0.png'), pygame.image.load('sprite_1.png'), pygame.image.load('sprite_2.png')]
class Player:
def __init__(self, x, y, width, height):
self.x = x
self.y = y
self.width = width
self.height = height
self.vel = 4
self.left = False
self.right = False
self.standing = True
self.walk_count = 0
self.hitbox = (self.x + 2, self.y + 26, 123, 45)
def draw(self, win):
if self.walk_count + 1 >= 12:
self.walk_count = 0
if not self.standing:
if self.left:
win.blit(walk_left[self.walk_count // 6], (self.x, self.y))
self.walk_count += 1
elif self.right:
win.blit(walk_right[self.walk_count // 6], (self.x, self.y))
self.walk_count += 1
else:
win.blit(standing[self.walk_count // 4], (self.x, self.y))
self.walk_count += 1
self.hitbox = (self.x + 2, self.y + 26, 123, 45)
pygame.draw.rect(win, (255, 0, 0), self.hitbox, 2)
def move():
if keys[pygame.K_LEFT] and man.x > man.vel or keys[pygame.K_a] and man.x > man.vel:
man.x -= man.vel
man.left = True
man.right = False
man.standing = False
elif keys[pygame.K_RIGHT] and man.x < 500 - man.width - man.vel:
man.x += man.vel
man.left = False
man.right = True
man.standing = False
else:
man.standing = True
class Enemy(pygame.sprite.Sprite):
asteroids = [pygame.image.load('rock0.png'), pygame.image.load('rock1.png'), pygame.image.load('rock2.png'),
pygame.image.load('rock3.png'), pygame.image.load('rock4.png')]
def __init__(self, y, width, height):
super().__init__()
self.width = width
self.height = height
self.vel = 1.5
x = random.randrange(screen_width - self.width * 2)
self.image = random.choice(self.asteroids)
self.rect = self.image.get_rect(topleft = (x, y))
def move(self):
self.rect.y += self.vel
class Projectile(pygame.sprite.Sprite):
def __init__(self, x, y, width, height, color):
super().__init__()
self.image = pygame.Surface((width, height))
self.image.fill(color)
self.rect = self.image.get_rect(topleft = (x, y))
self.vel = 5
def move(self):
self.rect.y -= self.vel
my_event_id = pygame.USEREVENT + 1
pygame.time.set_timer(my_event_id, 2000) # 2000 milliseconds = 2 seconds
class Unit:
def __init__(self):
self.last = pygame.time.get_ticks()
self.cooldown = 200
def fire(self):
now = pygame.time.get_ticks()
if now - self.last >= self.cooldown:
self.last = now
spawn_bullet()
def spawn_bullet():
if keys[pygame.K_SPACE]:
bullets.add(Projectile((man.x + man.width // 2), (man.y - 7), 3, 7, (255, 0, 0)))
def re_draw():
win.fill((0, 0, 0))
enemies.draw(win)
man.draw(win)
bullets.draw(win)
pygame.display.update()
delay = Unit()
man = Player(186, 400, 128, 128)
bullets = pygame.sprite.Group()
enemies = pygame.sprite.Group()
run = True
clock = pygame.time.Clock()
while run:
last = pygame.time.get_ticks()
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
elif event.type == my_event_id:
# spawn new enemy
enemies.add(Enemy(10, 64, 64))
for e in enemies:
e.move()
if e.rect.y > 500:
e.kill()
for b in bullets:
b.move()
if 0 > b.rect.y or b.rect.y > 500:
b.kill()
pygame.sprite.groupcollide(bullets, enemies, True, True)
keys = pygame.key.get_pressed()
move()
delay.fire()
clock.tick(60)
re_draw()
pygame.quit()