Python İki Class Arası İletişim

class a():
    def func2(self):
        self.no = 100

class b():
    aCopy = a()
    def func1(self):
        print(aCopy.fun2())
bCopy = b()
bCopy.func1()

class a():
    no = None
    def func2(self):
        self.no = 100
 
class b():
    aCopy = a()
    aCopy.func2()
    def func1(self):
        print(self.aCopy.no)
bCopy = b()
bCopy.func1()

class a():
    def func2(self):
        self.no = 100
        return self.no
 
class b(a):
    def __init__(self):
        super().__init__()

    def func1(self):
        print(self.func2())

bCopy = b()
bCopy.func1()

class Worker():
    def working(self):
        self.uis = Ui_MainWindow()
        self.txtMetin.append('DENEME BAŞARILI')
        
        
class Ui_MainWindow(Worker):
    worker = Worker()
    def setupUi(self, MainWindow):    
        self.txtMetin = QtWidgets.QTextEdit(self.splitter_3)
        self.txtMetin.setObjectName("txtMetin")