如何返回在类内部的函数中更改的变量，并在类外部的函数中使用它

Question

我正在尝试使用按钮（tkinter）尝试更改游戏的难度。 当我单击“简单”，“中等”或“困难”按钮时，应将整体难度分别更改为每个难度12,16,20的对应值。 但是，当我尝试在课堂外使用更改后的难度值时，出现错误：screen.ontimer（play，1000 //难度）NameError：未定义名称“ difficulty”

我试图返回self.difficulty，但是我不确定该怎么做。

class Application(Frame):
    def __init__(self, master):
        super().__init__(master)

        self.difficulty = -1

        self.grid()
        self.login = self.create_main()
        self.read = None

    def changeVariable1(self):
        self.difficulty = 12

    def changeVariable2(self):
        self.difficulty = 16

    def changeVariable3(self):
        self.difficulty = 20


    def diff(self):
        global radius
        if self.difficulty == 12:
            radius = (30)
        elif self.difficulty == 16:
            radius = (20)
        elif self.difficulty == 20:
            radius = (10)



    def create_read(self):
        read = Toplevel()
        Button(read, text="Easy", font='Helvetica 10 bold', command=self.changeVariable1).grid(row=3, column=2)
        Button(read, text="Medium", font='Helvetica 10 bold', command=self.changeVariable2).grid(row=3, column=3)
        Button(read, text="Hard", font='Helvetica 10 bold', command=self.changeVariable3).grid(row=3, column=4)

        return read

def play(app):
    rgb = (random(), random(), random())

    timeTaken = time() - startTime

    circles.append(my_circle(rgb))

    screen.title('SCORE: {}, TIME LEFT: {}'.format(score, int(round(gameLength - timeTaken, 0))))

    if time() - startTime > gameLength:
        screen.title('FINAL SCORE: {}'.format(score))
        screen.onclick(None)
        screen.clear()
    else:
        screen.ontimer(play, 1000 // app.difficulty)



root = Tk()

app = Application(root)

root.mainloop()

play(app)

我希望（通过按钮）选定的难度值将在功能play（）中使用。

Answer 1

您的函数在类之外，因此，如果要使用该类的任何成员，则应将类的对象作为外部函数中的参数传递，并抛出该对象，您可以使用该类的成员。

因此，请检查下面给出的更新代码。

def play(app):
    rgb = (random(), random(), random())

    timeTaken = time() - startTime

    circles.append(my_circle(rgb))

    screen.title('SCORE: {}, TIME LEFT: {}'.format(score, int(round(gameLength - timeTaken, 0))))

    if time() - startTime > gameLength:
        screen.title('FINAL SCORE: {}'.format(score))
        screen.onclick(None)
        screen.clear()
    else:
        screen.ontimer(play, 1000 // app.difficulty)



root = Tk()

app = Application(root)

root.mainloop()

play(app)