I'm creating a basic simulation in pygame and my object (an amoeba represented by a green square on the screen) has two methods. My update method is running fine, but the collide method is giving my an attribute error. By the way, since I have added many amoebae to the screen, I apply the methods to my amoebas group.

import pygame
import random
import time

from pygame.locals import (
    QUIT
)

pygame.init()

SCREEN_WIDTH = 500
SCREEN_HEIGHT = 500

screen = pygame.display.set_mode([500, 500])

amoebas = pygame.sprite.Group()
all_sprites = pygame.sprite.Group()

class Amoeba(pygame.sprite.Sprite):
    def __init__(self, maturingSpeed, x, y):
        super(Amoeba, self).__init__()
        self.surf = pygame.Surface((10,10))
        self.surf.fill((0, maturingSpeed, 0))
        self.rect = self.surf.get_rect(
            center=(
                x,
                y,
            )
        )
        self.speed = 2
        self.age = 1
        self.maturingSpeed = maturingSpeed    

    def update(self):
        if self.rect.left <= 0:
            direction = 1
        elif self.rect.right >= SCREEN_WIDTH:
            direction = 2
        elif self.rect.top <= 0:
            direction = 3
        elif self.rect.bottom >= SCREEN_HEIGHT:
            direction = 4
        else:
            direction = random.randint(1, 4)
            
        if direction == 1:
            self.rect.move_ip(self.speed, 0)
        elif direction == 2:
            self.rect.move_ip(-self.speed, 0)
        elif direction == 3:
            self.rect.move_ip(0, self.speed)
        elif direction == 4:
            self.rect.move_ip(0, -self.speed)

    def collide(self):  
        posList = [(amoeba.rect.left, amoeba.rect.top) for amoeba in list]
        length = len(posList)
        print(posList)
        print(length)
        for i in range(length):
          y = posList[i]
          for h in range(length):
              if posList[h] == y and h != i:
                  locationX = posList[i][0]
                  locationY = posList[i][1]
                  new_amoeba = Amoeba(150, locationX, locationY)
                  amoebas.add(new_amoeba)
                  all_sprites.add(new_amoeba)
              else:
                  pass

screen.fill((255, 255, 255))

for i in range(100):
        new_amoeba = Amoeba(150, random.randint(0, SCREEN_WIDTH), random.randint(0, SCREEN_HEIGHT))
        amoebas.add(new_amoeba)
        all_sprites.add(new_amoeba)

while True:
    time.sleep(0.000001)
    screen.fill((255, 255, 255))
    
    for event in pygame.event.get():
        if event.type == QUIT:
            break
    
    amoebas.update()
    amoebas.collide()

    for entity in all_sprites:
        screen.blit(entity.surf, entity.rect)
        
    pygame.display.flip()
    

pygame.quit()

I'm very new to OOP and this is my first complex program written in it, so any advice is welcome! Also, I know my question is pretty much identical to this one: Python is throwing AttributeError: 'Group' object has no attribute 'blitme' but unfortuantely I could not understand the answer so any help with that would also be welcome.

CodePudding user response：

pygame.sprite.Group.draw() and pygame.sprite.Group.update() are methods which are provided by pygame.sprite.Group.

The latter delegates to the update method of the contained pygame.sprite.Sprites — you have to implement the method. See pygame.sprite.Group.update():

Calls the update() method on all Sprites in the Group. [...]

The former uses the image and rect attributes of the contained pygame.sprite.Sprites to draw the objects — you have to ensure that the pygame.sprite.Sprites have the required attributes. See pygame.sprite.Group.draw():

Draws the contained Sprites to the Surface argument. This uses the Sprite.image attribute for the source surface, and Sprite.rect. [...]

Therefore you can call amoebas.update() and amoebas.draw(screen), but you can't call amoebas.collide().

You must call the collide methods in a loop:

for amoeba in amoebas;
    amoeba.collide()