Python PyQt5: How to show an error message with PyQt5

Question

In normal Python (3.x) we always use showerror() from the tkinter module to display an error message but what should I do in PyQt5 to display exactly the same message type as well?

Asked By: Ramón Wilhelm

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Source

Answer 1

The following should work:

msg = QMessageBox()
msg.setIcon(QMessageBox.Critical)
msg.setText("Error")
msg.setInformativeText(e)
msg.setWindowTitle("Error")

It is not the exact same message type (different GUI’s) but fairly close.
e is the expression for an Error in python3

Hope that helped,
Narusan

Answered By: Narusan

Answer 2

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_()

Answered By: mfitzp

Answer 3

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

Answered By: ZF007

Answer 4

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_()

Answered By: NShiell

Answer 5

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")

Answered By: Karam Qusai

Answer 6

Assuming you are in a QWidget from which you want to display an error message, you can simply use QMessageBox.critical(self, "Title", "Message"), replace self by another (main widget for example) if you are not is a QWidget class.

Edit: even if you are not in a QWidget (or don’t want to inherit from it), you can just use None as parent with for instance QMessageBox.critical(None, "Title", "Message").

Edit, here is an example of how to use it:

# -*-coding:utf-8 -*

from PyQt5.QtWidgets import QApplication, QMessageBox
import sys

# In this example, success is False by default, and
#  - If you press Cancel, it will ends with False,
#  - If you press Retry until i = 3, it will end with True


expectedVal = 3


def MyFunction(val: int) -> bool:
    return val == expectedVal


app = QApplication(sys.argv)
i = 1
success = MyFunction(i)
while not success:
    # Popup with several buttons, manage below depending on choice
    choice = QMessageBox.critical(None,
                                  "Error",
                                  "i ({}) is not expected val ({})".format(i, expectedVal),
                                  QMessageBox.Retry | QMessageBox.Cancel)
    if choice == QMessageBox.Retry:
        i += 1
        print("Retry with i = {}".format(i))
        success = MyFunction(i)
    else:
        print("Cancel")
        break

if success:
    # Standard popup with only OK button
    QMessageBox.information(None, "Result", "Success is {}".format(success))
else:
    # Standard popup with only OK button
    QMessageBox.critical(None, "Result", "Success is {}".format(success))

Answered By: gluttony

Python PyQt5: How to show an error message with PyQt5

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