向 init 添加参数并创建实例答案

【问题标题】：Adding parameters to init and create instance向 init 添加参数并创建实例
【发布时间】：2021-03-19 12:09:12
【问题描述】：

我想让我的班级的两个变量动态化，因此它们具有不同的值，具体取决于为游戏选择的难度。我在__init__ 中做错了什么还是问题出在哪里？如果我从__init__ 中删除两个参数speed_top_border, speed_bottom_border 并输入静态值，一切都会正常工作。

# Obstacle class
class Obstacle(object):

    # Init
    def __init__(self, speed_top_border, speed_bottom_border):
        self.obstacleImg = 'rock.png'
        self.obstacleX = random.randint(700, 800)
        self.obstacleY = random.randint(0, ScreenHeight - 64)
        self.obstacleX_change = random.uniform(self.speed_top_border, self.speed_bottom_border)

# Keep window running (Infinite-Loop)
running = 1

# Menu-loop
while running == 1:

    # Insert Background
    screen1.blit(background, (0, 0))

    for event in pygame.event.get():

        # Quit game
        if event.type == pygame.QUIT:
            running = 0

        if event.type == pygame.KEYDOWN:

            # Difficulty easy
            if event.key == pygame.K_1:
                speed_top_border = -1
                speed_bottom_border = -0.5

            # Start game
            if event.key == pygame.K_SPACE:
                running = 2

# Game While-Loop
    while running == 2:

# Creation of instancet of class obstacle each iteration
        if timer1_current - timer1_start >= interval:
            timer1_start = time.time()  # Timer of start set to current time
            obstacle = Obstacle(speed_top_border, speed_bottom_border)  # Create instance of class obstacle
            obstacle_list.append(obstacle)  # Append instance to list
            print(obstacle)  # Print created instance for check
            score += 100 * score_multiplier  # Increase score

错误信息

Traceback (most recent call last):
  File "C:\Users\Timo\PycharmProjects\2DFlugzeugspiel\main.py", line 221, in <module>
    obstacle = Obstacle(speed_top_border, speed_bottom_border)  # Create instance of class obstacle
  File "C:\Users\Timo\PycharmProjects\2DFlugzeugspiel\main.py", line 89, in __init__
    self.obstacleX_change = random.uniform(self.speed_top_border, self.speed_bottom_border)
AttributeError: 'Obstacle' object has no attribute 'speed_top_border'

【问题讨论】：

究竟是什么在这里不能正常工作？如果您遇到错误，请在您的问题中包含完整的错误回溯。如果您没有得到预期的行为，请说明您的实际行为与预期行为是什么。
@ThierryLathuille 哦，对不起，我添加了它
请始终包含 complete 错误回溯...
另外，请注意您将speed_top_border 传递给__init__，但您从未将其存储在任何地方。您可能打算使用self.speed_top_border = speed_top_border 创建一个属性。
@ThierryLathuille 感谢您的提示。我现在添加了完整的消息

标签： python class object parameters pygame

【解决方案1】：

您永远不会在__init__ 中定义self.speed_top_border、self.speed_bottom_border，而是尝试在self.obstacleX_change = random.uniform(self.speed_top_border, self.speed_bottom_border) 中使用它们

如果你想拥有这些属性 - 在使用它们之前定义它们

class Obstacle(object):

    def __init__(self, speed_top_border, speed_bottom_border):
        self.obstacleImg = 'rock.png'
        self.obstacleX = random.randint(700, 800)
        self.obstacleY = random.randint(0, ScreenHeight - 64)
        self.speed_top_border = speed_top_border
        self.speed_bottom_border = speed_bottom_border
        self.obstacleX_change = random.uniform(self.speed_top_border, self.speed_bottom_border)

【讨论】：