class ExtendedTreeWidgetItem(QTreeWidgetItem):

    def __init__(self, *args, **kwargs):
        super(ExtendedTreeWidgetItem, self).__init__(*args, **kwargs)
        self.rescueFile = None

    def setRescueFile(self, rFile):
        self.rescueFile = rFile

    def getRescueFile(self):
        return self.rescueFile



class RescueFile:

    def __init__(self, path):
        self.path = path
        self.ischecked = True

    def isChecked(self):
        return self.ischecked

    def setChecked(self, checked):
        if isinstance(checked, bool):
            self.ischecked = checked
        elif isinstance(checked, Qt.CheckState):
            self.ischecked = True if checked == Qt.Checked else False
        print(self.path, self.ischecked)

****
...
self.treeWidget.itemChanged.connect(self.singleClickTreeWidget)
...
****


def singleClickTreeWidget(self, widgetItem, column):
        parent = widgetItem.parent()
        if parent and parent.checkState(0) == Qt.Unchecked:
            widgetItem.setCheckState(0, Qt.Unchecked)
            return

        checkState = widgetItem.checkState(0)

        widgetItem.setCheckState(0, checkState)
        rescue_file = widgetItem.getRescueFile()
        **# I CAN GET THE RESCUE FILE OBJECT HERE FROM**
        if rescue_file:
            rescue_file.setChecked(checkState)

        self.iterateThroughChildren(widgetItem, checkState)



def iterateThroughChildren(self, item, checkState):
    for i in range(item.childCount()):
        child = item.child(i)
        child.setCheckState(0, checkState)
        **# I CAN'T GET ANY FIND HERE ANYMORE**
        rescue_file = item.getRescueFile()
        if rescue_file:
            rescue_file.setChecked(checkState)
        else:
            self.iterateThroughChildren(child, checkState)