Help with Creating Your First App Tutorial

I’m struggling a bit with the very first lesson. I’m following along the video at the top of the page since the codeblocks on the page are different and don’t seem to be working for me (missing imports as far as I can tell). I’ve gotten to the part where we use a class to create the window but when I attempt to change the title of the window it doesn’t change. Code is below, I’m on Windows 10 with Python 3.7.4. and Python 3.9 (I just reinstalled it as a test)

import sys
from PySide2.QtWidgets import *
from PySide2.QtCore import *
from PySide2.QtGui import *

class MainWindow(QMainWindow):    

    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args,**kwargs)
        self.setWindowTitle('Awesome App')

app = QApplication(sys.argv)
window = QWidget()
window.show() # IMPORTANT! Windows are hidden by default.

app.exec_()

Setting the title with window.setWindowTitle(‘whatever’) does work though.

window = MainWindow() worked. I’m guessing this is an error in the lesson. Further down the variable is changed though to that. I didn’t notice it changes