CodersLegacy PyQt5 tutorial

from PyQt5 import QtWidgets
from PyQt5.QtWidgets import QApplication, QMainWindow
import sys
 
def window():
    app = QApplication(sys.argv)
    win = QMainWindow()
    win.setGeometry(400,400,500,300)
    win.setWindowTitle("CodersLegacy")
 
    #.....
 
    win.show()
    sys.exit(app.exec_())
     
window()