Can't use my widget Qcombobox in method, why?

Question

New to pyQt, I'm trying to fill a Qcombobox with a list of items, and then, to retrieve the text selected by the user. Everything works fine except that, when CurrentIndexChanged signal is triggered, I can't get the index of the selection, but not the text, with .currentText() in my method, because I have an error telling me that I can't call my widget in the method. Python does not recognize my QCombobox in the method, so that I can't use .currentText(), and I can't figure why.

Thanks !

See my code below.

class MainWindow(QMainWindow):        
    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)

        self.setWindowTitle("Votre territoire")

        layout = QVBoxLayout()

        listCom = self.getComINSEE()
        cbCommunes = QComboBox()
        cbCommunes.addItems(listCom)
        cbCommunes.currentIndexChanged.connect(self.selectionChange)

        layout.addWidget(cbCommunes)

        cbCommunes = QWidget()
        cbCommunes.setLayout(layout)

        self.setCentralWidget(cbCommunes)


    def getComINSEE(self):
        # some code to fill my list com
        return com

    def selectionChange(self, i):
        # Error : unhandled AttributeError "'MainWindow' object has no attribute 'cbCommunes'"
        texte = self.cbCommunes.currentText()
        print(f"Index {i} pour la commune {i}")

app = QApplication(sys.argv)

window = MainWindow()
window.show()

app.exec()

Answer 1

To get access to an object in any class method, you need to make this object an attribute of the class.

change cbCommunes toself.cbCommunes - everywhere.

from PyQt5.Qt import *


class MainWindow(QMainWindow):        
    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)
        self.setWindowTitle("Votre territoire")

        listCom = self.getComINSEE()
        self.cbCommunes = QComboBox()
        self.cbCommunes.addItems(listCom)
        self.cbCommunes.currentIndexChanged.connect(self.selectionChange)

        centralwidget = QWidget()
        self.setCentralWidget(centralwidget)

        layout = QVBoxLayout(centralwidget)
        layout.addWidget(self.cbCommunes)

    def getComINSEE(self):
        # some code to fill my list com
        com = ['item 1', 'item 2', 'item 3', 'item 4', 'item 5',]
        return com

    def selectionChange(self, i):
        # Error : unhandled AttributeError "'MainWindow' object has no attribute 'cbCommunes'"
        texte = self.cbCommunes.currentText()
        print(f"Index {i} pour la commune {i}, texte -> {texte}")


if __name__ == '__main__':
    import sys
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())