Question

我有一个抽象类ship。

from abc import ABC, abstractmethod
class ship(ABC):
    def __init__(self):
         ...

    @abstractmethod
    def do_stuff(self,stuff,things):
         pass

我有多个继承自它的类（destroyer，cruiser，patrol_boat等等。）

class carrier(ship):
    def __init__(self):
         ....
    def do_stuff(self,stuff,things):
         ....

目前，如果我要添加，请说def do_more_stuff(self):到ship

class ship(ABC):
    def __init__(self):
         ...

    @abstractmethod
    def do_stuff(self,stuff,things):
         pass

    @abstractmethod
    def do_more_stuff(self,stuff,things):
        pass

在我将其重新输入控制台之前，更改不会影响任何子类。我该如何改变？

Answer 1

如果你真的从头开始重新定义一个类，它就是一个不同的类;子类仍然继承旧版ship。您不能只定义一个名为ship的新类，并希望子类能够神奇地找到它。

通常情况下，如果您想在创建后使用ship进行猴子补丁添加新方法，您可以执行以下操作：

def do_more_stuff(self,stuff,things):
    pass
ship.do_more_stuff = do_more_stuff

但不幸的是，abstractmethod are an explicit exception to this rule ABC为using System; using OpenTK; using OpenTK.Graphics; using OpenTK.Graphics.OpenGL; namespace OpenGLLine { static class Program { static OpenTK.GameWindow gw; static int shaderProgram; static int vertexInfo; static int lineVertexBuffer; static int vertexCount; [STAThread] static void Main() { gw = new OpenTK.GameWindow(800, 600, OpenTK.Graphics.GraphicsMode.Default, "Game", OpenTK.GameWindowFlags.FixedWindow); Initialize(); gw.RenderFrame += Gw_RenderFrame; gw.Closed += Gw_Closed; gw.Run(60); } private static void Gw_Closed(object sender, EventArgs e) { CleanUp(); } private static void Initialize() { int vshader = GL.CreateShader(ShaderType.VertexShader); GL.ShaderSource(vshader, @"#version 130 in vec2 vPosition; void main() { gl_Position = vec4(vPosition, -1.0, 1.0); }"); GL.CompileShader(vshader); int fshader = GL.CreateShader(ShaderType.FragmentShader); GL.ShaderSource(fshader, @"#version 130 out vec4 fragColor; void main() { fragColor = vec4(1.0, 1.0, 1.0, 1.0); }"); GL.CompileShader(fshader); shaderProgram = GL.CreateProgram(); GL.AttachShader(shaderProgram, vshader); GL.AttachShader(shaderProgram, fshader); GL.LinkProgram(shaderProgram); GL.DetachShader(shaderProgram, vshader); GL.DetachShader(shaderProgram, fshader); GL.UseProgram(shaderProgram); lineVertexBuffer = GL.GenBuffer(); Vector2[] lineVertices = { new Vector2(0, 0), new Vector2(.5f, .5f) }; vertexCount = lineVertices.Length; GL.BindBuffer(BufferTarget.ArrayBuffer, lineVertexBuffer); GL.BufferData(BufferTarget.ArrayBuffer, System.Runtime.InteropServices.Marshal.SizeOf(lineVertices[0]) * vertexCount, lineVertices, BufferUsageHint.StreamDraw); vertexInfo = GL.GenVertexArray(); GL.BindVertexArray(vertexInfo); int locVPosition = GL.GetAttribLocation(shaderProgram, "vPosition"); GL.EnableVertexAttribArray(locVPosition); GL.VertexAttribPointer(locVPosition, 2, VertexAttribPointerType.Float, false, System.Runtime.InteropServices.Marshal.SizeOf(lineVertices[0]), 0); GL.BindVertexArray(0); GL.BindBuffer(BufferTarget.ArrayBuffer, 0); GL.UseProgram(0); } static void CleanUp() { GL.DeleteProgram(shaderProgram); GL.DeleteVertexArray(vertexInfo); GL.DeleteBuffer(lineVertexBuffer); } private static void Gw_RenderFrame(object sender, OpenTK.FrameEventArgs e) { GL.ClearColor(Color4.Black); GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit); GL.BindBuffer(BufferTarget.ArrayBuffer, lineVertexBuffer); GL.UseProgram(shaderProgram); GL.BindVertexArray(vertexInfo); GL.DrawArrays(PrimitiveType.LineStrip, 0, vertexCount); GL.BindVertexArray(0); GL.BindBuffer(BufferTarget.ArrayBuffer, 0); GL.UseProgram(0); gw.SwapBuffers(); } } }：

不支持动态地向类添加抽象方法，或者在创建方法或类时尝试修改方法或类的抽象状态。

您必须事先完全定义抽象基类，或者如果要将新抽象方法添加到基类中，请稍后重新定义整个类层次结构。

更新从抽象类继承的类

1 个答案: