46937773.py

from PyQt5 import QtWidgets

from testCloseEventDialog import TestDialog
from testCloseEventMain import TestMain


class newDialog(QtWidgets.QDialog, TestDialog):
    def __init__(self, *args, **kwargs):
        QtWidgets.QDialog.__init__(self, *args, **kwargs)
        self.setupUi(self)
        self.btnClose.clicked.connect(self.exitWindow)

    def exitWindow(self):
        print("close button pressed in test dialog window")
        self.close()

    def closeEvent(self, event):
        print("executing close event in test dialog window")
        QtWidgets.QDialog.closeEvent(self, event)


class newMain(QtWidgets.QMainWindow, TestMain):
    def __init__(self, *args, **kwargs):
        QtWidgets.QMainWindow.__init__(self, *args, **kwargs)
        self.setupUi(self)

        self.btnOpenDialog.clicked.connect(self.openDialog)
        self.btnClose.clicked.connect(self.closeBtnPushed)
        self.popNewDialog = newDialog()

    def openDialog(self):
        self.popNewDialog.show()

    def closeBtnPushed(self):
        print("close button pressed in main window")
        self.close()

    def closeEvent(self, event):
        self.popNewDialog.close()
        print("executing closing event in main window")
        QtWidgets.QMainWindow.closeEvent(self, event)


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = newMain()
    w.show()
    sys.exit(app.exec_())

testCloseEventDialog.py

from PyQt5 import QtCore, QtGui, QtWidgets


class TestDialog(object):
    def setupUi(self, DialogTest):
        DialogTest.resize(200, 100)
        DialogTest.setWindowTitle("DialogTest")

        self.btnClose = QtWidgets.QPushButton()
        self.btnClose.setText("Close")

        self.verticalLayout = QtWidgets.QVBoxLayout(DialogTest)
        self.verticalLayout.addWidget(self.btnClose)

        QtCore.QMetaObject.connectSlotsByName(DialogTest)


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    DialogTest = QtWidgets.QWidget()
    ui = TestDialog()
    ui.setupUi(DialogTest)
    DialogTest.show()
    sys.exit(app.exec_())

testCloseEventMain.py

from PyQt5 import QtCore, QtGui, QtWidgets


class TestMain(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(300, 100)

        self.centralwidget = QtWidgets.QWidget(MainWindow)

        self.btnOpenDialog = QtWidgets.QPushButton()
        self.btnClose = QtWidgets.QPushButton()

        self.verticalLayout = QtWidgets.QVBoxLayout(self.centralwidget)
        self.verticalLayout.addWidget(self.btnOpenDialog)
        self.verticalLayout.addWidget(self.btnClose)

        MainWindow.setCentralWidget(self.centralwidget)
        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.btnOpenDialog.setText(_translate("MainWindow", "Open Dialog"))
        self.btnClose.setText(_translate("MainWindow", "Close"))


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = TestMain()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())