assigning a variable to instance of a class and then keep updating it

Question

I want to create an instance of a class that holds an external variable. The class should keep updating the external variable that is being changed continuously.

Here is my code that will explain what I mean to say. However this code will not update the variable assigned to the class because my approach is not correct.

class Update_variable(QtCore.QThread):
    def __init__(self, VariablName):
        QtCore.QThread.__init__(self)
        self.VariablName = VariablName

    def run(self):
        while True:
            variable = self.VariablName
            print("Value updated to: ", variable)           
            time.sleep(1.0)

if __name__ == '__main__':
    var1 = 0.0
    var2 = 1.1
    update_var1 = Update_variable(var1)
    update_var2 = Update_variable(var2)
    update_var1.start()
    update_var2.start()
    while True:
        var1 = random()
        var2 = random()
        print("New value for var1: ",var1)
        print("New value for var2: ",var2)
        time.sleep(1.0)

Answer 1

You can't do this way, because variables are passed by assignment.

But the Python documentation itself gives us some options: https://docs.python.org/3/faq/programming.html#how-do-i-write-a-function-with-output-parameters-call-by-reference