Python PyQt5: How to show an error message with PyQt5

Don't forget to call .exec_() to display the error:

from PyQt5.QtWidgets import QMessageBox

msg = QMessageBox()
msg.setIcon(QMessageBox.Critical)
msg.setText("Error")
msg.setInformativeText('More information')
msg.setWindowTitle("Error")
msg.exec_()

All above options didn't work for me using Komodo Edit 11.0. Just had returned "1" or if not implemented "-1073741819".

Usefull for me was: Vanloc's solution.

def my_exception_hook(exctype, value, traceback):
    # Print the error and traceback
    print(exctype, value, traceback)
    # Call the normal Exception hook after
    sys._excepthook(exctype, value, traceback)
    sys.exit(1)

# Back up the reference to the exceptionhook
sys._excepthook = sys.excepthook

# Set the exception hook to our wrapping function
sys.excepthook = my_exception_hook

To show a message box, you can call this def:

from PyQt5.QtWidgets import QMessageBox, QWidget

MainClass(QWidget):
    def __init__(self):
        super().__init__()

    def clickMethod(self):
        QMessageBox.about(self, "Title", "Message")

Qt includes an error-message specific dialog class QErrorMessage which you should use to ensure your dialog matches system standards. To show the dialog just create a dialog object, then call .showMessage(). For example:

error_dialog = QtWidgets.QErrorMessage()
error_dialog.showMessage('Oh no!')

Here is a minimal working example script:

import PyQt5
from PyQt5 import QtWidgets

app = QtWidgets.QApplication([])

error_dialog = QtWidgets.QErrorMessage()
error_dialog.showMessage('Oh no!')

app.exec_()