import sys

from PyQt5.QtWidgets import QMainWindow, QPushButton, QMessageBox, QApplication


class MainWindow(QMainWindow):

    def __init__(self):
        super().__init__()
        self.setWindowTitle('My App')

        button = QPushButton('Press me for a dialog!')
        button.setCheckable(True)
        button.clicked.connect(self.button_clicked)
        self.setCentralWidget(button)

    def button_clicked(self, is_checked):
        # button = QMessageBox.question(self, "Question dialog", "The longer message")
        button = QMessageBox.critical(
            self,
            'Oh dear!',
            'Somthing went very wrong',
            buttons=QMessageBox.Discard
            | QMessageBox.NoToAll
            | QMessageBox.Ignore,
            defaultButton=QMessageBox.Discard,
        )

        if button == QMessageBox.Discard:
            print("Discard!")
        elif button == QMessageBox.NoToAll:
            print("No to all!")
        else:
            print("Ignore!")


app = QApplication(sys.argv)
window = MainWindow()
window.show()
sys.exit(app.exec_())