使用 python 类（OOP）创建功能性海龟对象？

Question

I'm currently coding in python to create a somewhat similar game to 'Space Invaders'. It was going well until I tried to make all of my invader objects (which are turtles) by using a class, so I could easily manipulate the number of enemies I wanted when I adjust the difficulty.

However now I have done this I have removed functionality to the TURTLE objects as they are now seen as CLASS OBJECTS instead. Therefore I cannot use turtle module features such as [object].xcor and [object].ycor which are somewhat essential.

Here is the code that makes the class of objects:

class invaders():
def __init__(self, speed, position):
    self = turtle.Turtle()   # how I thought I could make them turtle objects (didn't work)
    self.color('red')   
    self.shape('circle')
    self.up()
    self.setposition(position)
    self.speed(speed)

def change_speed(newSpeed):
    invader.speed(newSpeed)   # use to make new speed if changing difficulty  #variable.changeSpeed(newSpeed)

def change_position(x, y):
    invader.setposition(x, y)

I have also attached a photo below so you can see the difference between the two objects I am talking about.

Answer 1

Objects can contain another class instance or objects can be ( subclass ) an instance of another class. What you initially described and attempted was subclassing , what you settled for was contain . Here's a (Python3) example of how we might subclass turtle to make an invader:

from turtle import Turtle, Screen

class Invader(Turtle):
    def __init__(self, speed, position):
        super().__init__(shape='circle', visible=False)
        self.color('red')
        self.penup()
        self.setposition(position)
        self.speed(speed)
        self.showturtle()

    def change_speed(self, newSpeed):
        self.speed(newSpeed)

    def change_position(self, x, y):
        self.setposition(x, y)

invader = Invader('slowest', (100, 100))

invader.change_position(-100, -100)

invader.change_speed('fastest')

invader.pendown()  # try an original turtle method

invader.change_position(100, -100)

screen = Screen()

screen.exitonclick()

Now when we create an invader instance, it describes itself as such:

>>> fred = Invader("normal", (0, 0))
>>> fred
<__main__.Invader object at 0x1021784e0>
>>> 

Answer 2

Self = turtle.Turtle() should be self.turtle = turtle.Turtle()

Thanks @Stack

Answer 3

实际上，您可以使用 self.turtle.color("red") 来访问海龟的颜色属性。