py python ui turn when the need to add a bit of code otherwise no reaction

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow
import test  # module test.py

if __name__ == '__main__':
 app = QApplication(sys.argv)
 myMainWindow = QMainWindow()
 myUi = test.Ui_MainWindow()
 myUi.setupUi(myMainWindow)
 myMainWindow.show()
 sys.exit(app.exec_())