new_contents: #!/usr/bin/python
  
  import sys
  from PyQt5.QtWidgets import QMainWindow, QDesktopWidget, QApplication
  
  class MainWindow(QMainWindow):
  
      def __init__(self):
          super(MainWindow, self).__init__()
          self.init_UI()
  
      def init_UI(self):
          WINDOW_WIDTH = 800
          WINDOW_HEIGHT = 800
          self.resize(WINDOW_WIDTH, WINDOW_HEIGHT)
          self.center()
          self.setWindowTitle('Test GUI')
          self.show()
  
      def center(self):
          screen = QDesktopWidget().screenGeometry()
          size = self.geometry()
          self.move((screen.width()-size.width())/2,
                    (screen.height()-size.height())/2)
  
  # if __name__ == '__main__':
  app = QApplication(sys.argv)
  main_window = MainWindow()
  sys.exit(app.exec_())
  
subject: Add gui.py