Python Qt5 : toolbar example.

This is a simple example with PyQt5 python module and python 3.6.4 version.
The example is about how to create a toolbar with PyQt5.
The base of this source code is the create a default window application.
I create a toolbar and I add an action to this toolbar.
The name of the toolbar is my_toolbar.
The action is named one_action.
This action is linked to a python function named action_one.
I add to my source code another function named alert.
This is good for debugging part to handle with errors and displaying alerts.
Let's see the source code:

from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
import sys

class MainWindow(QMainWindow):

    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)
        self.status = QStatusBar()
        self.setStatusBar(self.status)
        my_toolbar = QToolBar("toolbar")
        my_toolbar.setIconSize(QSize(48, 48))
        self.addToolBar(my_toolbar)
        
        one_action = QAction(QIcon(), "Action one", self)        
        one_action.setStatusTip("Action one on toolbar")
        one_action.triggered.connect(self.action_one)
        my_toolbar.addAction(one_action)
        
        self.setWindowTitle("Window PyQt5 - 001")
        self.show()

    def action_one(self):
        print("Action one")

    def alert(self, s):
        """
        This handle errors and displaying alerts.
        """
        err = QErrorMessage(self)
        err.showMessage(s)

if __name__ == '__main__':

    app = QApplication(sys.argv)
    app.setApplicationName("Window PyQt5 - 001")

    window = MainWindow()
    app.exec_()