first try

grum.py

@@ -0,0 +1,14 @@
+#!/usr/bin/env python
+
+import sys
+from PyQt5.QtWidgets import QApplication
+from mainwin import MainWindow
+
+
+app = QApplication(sys.argv)
+mw = MainWindow()
+mw.show()
+sys.exit(app.exec())
+
+
+