"Particle Object Not Defined" 错误信息

Question

我目前正在尝试编写一个程序，在屏幕上创建 20 个随机点，并计算连续单击它们所需的时间（它们不应一次全部出现）。显然，我的代码尚未完成，但我不断收到一条错误消息，指出 "Particle object isn't iterable." 谁能帮帮我？谢谢！（我知道我的粒子列表也有点荒谬，但你能做什么？:-)）

import pygame
import random
import math
import sys

background_colour = (255,255,255)
(width, height) = 600,500

screen = pygame.display.set_mode((width, height))
pygame.display.set_caption('DBS Test')

circle1 = (pygame.draw.circle(screen, (255, 255, 255), (300, 250), 25, 25))


def addVectors(angle1, length1, angle2, length2):
    x  = math.sin(angle1) * length1 + math.sin(angle2) * length2
    y  = math.cos(angle1) * length1 + math.cos(angle2) * length2

    angle = 0.5 * math.pi - math.atan2(y, x)
    length  = math.hypot(x, y)

    return (angle, length)

def findParticle(particles, x, y):
    for p in particles:
        if math.hypot(p.x-x, p.y-y) <= p.size:
            return p
    return None

class Particle:
    def __init__(self, position, size):
        self.x, self.y = position
        self.size = size
        self.colour = (255, 0, 0)
        self.thickness = 20
    def display(self):
        pygame.draw.circle(screen, self.colour, (self.x, self.y), self.size, self.thickness)

particle_one = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_two = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_three = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_four = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_five = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_six = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_seven = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_eight = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_nine = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_ten = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_eleven = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_twelve = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_thirteen = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_fourteen = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_fifteen = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_sixteen = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_seventeen = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_eighteen = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_nineteen = Particle((random.randint(0,600), random.randint(0,500)), 20)
particle_twenty = Particle((random.randint(0,600), random.randint(0,500)), 20)

particle_one.display()

selected_particle = None
running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        elif event.type == pygame.MOUSEBUTTONDOWN:
            (mouseX, mouseY) = pygame.mouse.get_pos()
            selected_particle = findParticle(particle_one, mouseX, mouseY)
        elif event.type == pygame.MOUSEBUTTONUP:
            selected_particle = None

    if selected_particle:
        (mouseX, mouseY) = pygame.mouse.get_pos()
        dx = mouseX - selected_particle.x
        dy = mouseY - selected_particle.y
        particle_two.display()


pygame.display.flip()


def main():
pass

if __name__ == '__main__':
main()

Answer 1

问题是您传递了单个粒子实例，但 findParticle 函数需要一个可迭代对象（例如列表）。您可以在程序启动时创建一个粒子列表，然后将此列表传递给函数。

import pygame
import random
import math


pygame.init()  # Initialize all pygame modules.
background_colour = (255,255,255)
screen = pygame.display.set_mode((600, 500))
clock = pygame.time.Clock()


def findParticle(particles, x, y):
    for p in particles:
        if math.hypot(p.x-x, p.y-y) <= p.size:
            return p
    return None


class Particle:

    def __init__(self, position, size):
        self.x, self.y = position
        self.size = size
        self.colour = (255, 0, 0)

    def display(self):
        pygame.draw.circle(screen, self.colour, (self.x, self.y), self.size)


# Create a list for the particles.
particles = []
for _ in range(20):
    particle = Particle((random.randint(0,600), random.randint(0,500)), 20)
    particles.append(particle)  # Append the new particle.

# Or use a list comprehension:
# particles = [Particle((random.randint(0,600), random.randint(0,500)), 20) for _ in range(20)]

selected_particle = None
running = True

while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        elif event.type == pygame.MOUSEBUTTONDOWN:
            (mouseX, mouseY) = pygame.mouse.get_pos()
            # Now pass the particles list instead of a single particle.
            selected_particle = findParticle(particles, mouseX, mouseY)
        elif event.type == pygame.MOUSEBUTTONUP:
            selected_particle = None

    if selected_particle:
        # Set the x and y-position of the particle at the same time.
        selected_particle.x, selected_particle.y = pygame.mouse.get_pos()

    # Clear the screen, then draw the particles.
    screen.fill(background_colour)
    for particle in particles:
        particle.display()

    pygame.display.flip()
    clock.tick(30)  # Limits the frame rate to 30 fps.

pygame.quit()

"Particle Object Not Defined" 错误信息

"Particle Object Not Defined" Error Message

python

pygame

particles

python-3.x