为什么我得到不同的结果

Question

为什么在绘制到屏幕的过程中使用组精灵对象的方法更新时会得到不同的结果。 当通过调用方法时，我只会得到一行精灵，而当我运行循环并将每个精灵的y轴移动一个时，整个群（几行）就会向下移动。 这是代码

drop.py

import pygame
from pygame.sprite import Sprite


class Drop(Sprite):
"""Class that represent single drop in rain"""

    def __init__(self, settings, screen):
        """Initialize drop and sets its starting position"""
        super().__init__()
        self.screen = screen
        self.settings = settings

        #Load drop image and sets its rect attribute
        self.image = pygame.image.load('images/drop.bmp')
        self.rect = self.image.get_rect()

        #Start each drop on top-left on the screen
        self.rect.x = self.rect.width
        self.rect.y = self.rect.height

        #store drop exact position
        self.y = float(self.rect.y)


    def update(self):
        self.y += 1
        self.rect.y = self.y        

我将所有功能存储在单独的文件中。 只是为了减少混乱。 函数update_screen（）在代码中描述的注释中的位置处的问题，我不明白为什么会导致通过精灵循环的差异，以及那样的方式改变y轴并使整个对象移动，但是当我使用精灵对象的方法时。update（）他们在分组中，我只能在屏幕上移动部分分组。

func_rain.py

import pygame
import sys
from drop import Drop
from time import sleep

def create_rain(settings, screen, drops):
    """Create a fleet of drops."""
    #Create an drop and find the number of drops in a row and number rows

    drop = Drop(settings, screen)
    number_drops_x = get_number_drops_x(settings, drop.rect.width)
    number_rows = get_number_rows(settings, drop.rect.height)

    for row_number in range(number_rows):
        for drop_number in range (number_drops_x):
            create_drop(settings, screen, drops, drop_number, row_number)      

def get_number_drops_x(settings, drop_width):    
    """Determine the number of drops that fit in a row."""
    available_space_x = settings.screen_width - 2 * drop_width
    number_drops_x = int(available_space_x / (2 * drop_width))
    return number_drops_x


def get_number_rows(settings, drop_height):
    """Determine the number of rows of drops that fit on the screen."""
    available_space_y = (settings.screen_height -  drop_height)
    number_rows = int(available_space_y / (2 * drop_height))
    return number_rows


def create_drop(settings, screen, drops, drop_number, row_number):
    """Create drop and place it in the row"""

    drop = Drop(settings, screen)
    drop_width = drop.rect.width
    drop.x = drop_width + 2 * drop_width * drop_number
    drop.rect.x = drop.x
    drop.rect.y = drop.rect.height + 2 * drop.rect.height * row_number
    drops.add(drop)


def check_keydown_events(event):
    """Respond to key presses"""                     
    if event.key == pygame.K_q:
        sys.exit()


def check_events():
    """Respond to keypress and mouse events"""
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()

        elif event.type == pygame.KEYDOWN:
            check_keydown_events(event)


def update_screen(settings, screen, drops):
    """Update images on the screen and flip to the new screen."""
    # Redraw the screen during each pass through the loop.
    screen.fill(settings.bg_color)
#This loop
    for drop in drops:
        drop.rect.y += 1
"""Here is the problem!!!!!! if I use for loop just above I get whole group      
   consisting from 5 rows of drops (image has resolution 50*62 pix). But when 
   I use drops.update() commented below (no for loop) I get on screen only
   one row of drops."""
    #drops.update()
    drops.draw(screen)
    pygame.display.flip()

rain_settings.py

 class Settings():
    """A class to store all ran settings"""

    def __init__(self):
        #Screen settings
        self.screen_width = 1200
        self.screen_height = 800
        self.bg_color = (100, 100, 100)

最后一个主文件。 下雨了

import pygame
from rain_settings import Settings
import func_rain as fr
from pygame.sprite import Group

def run_rain():
    """Initialize pygame and screen object"""
    pygame.init()
    settings = Settings()
    screen = pygame.display.set_mode(
        (settings.screen_width, settings.screen_height))

    drops = Group()
    fr.create_rain(settings, screen, drops)

    while True:

        fr.check_events()
        fr.update_screen(settings, screen, drops)    


run_rain()

如果有人可以向我解释我在做什么错，我将不胜感激。 我不知道。 请

Answer 1

因此，我一直在玩耍，并且通过类方法更新来使精灵运动。

def update(self):
    self.rect.y += 1

尽管对我来说仍然是一个谜，为什么直接更改self.rect.y有效而间接更改y属性无效。