What method is 'correct' to share variables with pyqt Ui and Qthread?

Question

I've always wondered about what is the right way to share variable data with QThread and UI data. Well, for example,

#main.py
class MainUI(QMainWindow):
    def __init__(self):
        super().__init__()
        self.initUI()
        self.workerThread = Thread()
        self.workerThread.mySignal.connect(self.function_name)
#worker.py
class Thread(QThread):
    mySignal = pyqtSignal(str) 

    def __init__(self):    
        super().__init__()

    def run(self):
        self.mySignal.emit(some_string)

I know this code will emit and share "some_string" variable with MainUI class.

However; I don't think pyqt have an option to share variable data MainUI -> Thread

So, I am writing a code just like

self.workerThread.variable = None

What is desirable method to write a code?