How to pass data to an object of another class in python?

Question

Python

There is a form generated by QtDesigner

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        ...
        self.textEdit_3.setObjectName("textEdit_3")

main class:

from scripts import *
class ExampleApp(QtWidgets.QMainWindow, gui.Ui_MainWindow ):
    def __init__(self):
        super().__init__()
        self.setupUi(self)  
...

and there is a scripts.py module, in which there is one function, without a class yet:

def run_script_function( *args):
           self.textEdit_3.setPlainText(code)

and from this module you need to send data to textEdit_3. Tell me how to make it right so that it works