pyside2 dialog - uses https://github.com/mottosso/Qt.py

pyside2_dialog.py

import sys
from Qt import QtCore
from Qt import QtGui
from Qt import QtCompat
from Qt import QtWidgets


class my_dialog(QtWidgets.QDialog):
    def __init__(self):
        QtWidgets.QDialog.__init__(self, None, QtCore.Qt.WindowStaysOnTopHint)
 
        self.setWindowTitle('Append comment to export')
        # self.setWindowIcon()
        self.setSizeGripEnabled(True)
        self.setFixedWidth(500)
        
        # Works, should always stays on top now
        self.setModal(True)
        
        # Create widgets
        self.CommentInput = QtWidgets.QTextEdit()
        self.SaveButton = QtWidgets.QPushButton('Save')
        
        # Create layouts and add widgets
        # Make a group
        Group1 = QtWidgets.QGroupBox('Please record what changes have happened in this version')

        # make a layout for the group
        Group1Layout = QtWidgets.QGridLayout()
        
        # add widgets to the groups layout
        Group1Layout.addWidget(self.CommentInput)
        Group1Layout.addWidget(self.SaveButton)

        # assign the layout to the group
        Group1.setLayout(Group1Layout)
        
        # Create top layout
        Layout = QtWidgets.QVBoxLayout()
        
        # Assign widgets to the top layout
        Layout.addWidget(Group1)
        
        # Set dialog layout
        self.setLayout(Layout)
        
        # Add button signal to greetings slot
        self.SaveButton.clicked.connect(self.Save)

    def Save(self):
        """
        called by the button
        """
        self.accept()

    def GetValues(self):
        """
        Return Value method
        """
        return self.CommentInput.toPlainText()


def main():
    # Grab an instance already open (if already in an application)
    app = QtWidgets.QApplication.instance()

    # Create the Qt Application
    if app is None:
        app = QtWidgets.QApplication(sys.argv)

    # Create the dialog in memory (an instance of the class)
    my_dialog_instance = my_dialog()

    print('my_dialog_instance: {}'.format(my_dialog_instance))

    # if checks if it returns 1 or 0 and if so to cancel or accept the dialogs return
    if my_dialog_instance.exec_():
        # If the dialog was accepted, the object still persists and we can retrieve data from it
        print('my_dialog_instance.GetValues(): {}'.format(my_dialog_instance.GetValues()))
    else:
        print('dialog cancelled')


if __name__ == '__main__':
    main()