python pyqt5 QTreeWidget 动态添加节点

    operatorLayout = QHBoxLayout()
    addBtn = QPushButton("添加节点")
    updateBtn = QPushButton("修改节点")
    delBtn = QPushButton("删除节点")
    operatorLayout.addWidget(addBtn)
    operatorLayout.addWidget(updateBtn)
    operatorLayout.addWidget(delBtn)
    # 按钮的信号槽连接
    addBtn.clicked.connect(self.addTreeNodeBtn)
    updateBtn.clicked.connect(self.updateTreeNodeBtn)
    delBtn.clicked.connect(self.delTreeNodeBtn)

    self.tree = QTreeWidget(self)
    # 设置列数
    self.tree.setColumnCount(2)
    # 设置头的标题
    self.tree.setHeaderLabels(['Key', 'Value'])
    root = QTreeWidgetItem(self.tree)
    root.setText(0, 'root')
    root.setText(1, '0')

    child1 = QTreeWidgetItem(root)
    child1.setText(0, 'child1')
    child1.setText(1, '1')

    child2 = QTreeWidgetItem(root)
    child2.setText(0, 'child2')
    child2.setText(1, '2')

    child3 = QTreeWidgetItem(root)
    child3.setText(0, 'child3')
    child3.setText(1, '3')

    child4 = QTreeWidgetItem(child3)
    child4.setText(0, 'child4')
    child4.setText(1, '4')

    child5 = QTreeWidgetItem(child3)
    child5.setText(0, 'child5')
    child5.setText(1, '5')

    self.tree.addTopLevelItem(root)
    self.tree.clicked.connect(self.onTreeClicked)

    mainLayout = QVBoxLayout(self);
    mainLayout.addLayout(operatorLayout);
    mainLayout.addWidget(self.tree);
    self.setLayout(mainLayout)

def onTreeClicked(self, qmodelindex):
    item = self.tree.currentItem()
    print("key=%s ,value=%s" % (item.text(0), item.text(1)))

def addTreeNodeBtn(self):
    print('--- addTreeNodeBtn ---')
    item = self.tree.currentItem()
    node = QTreeWidgetItem(item)
    node.setText(0, 'newNode')
    node.setText(1, '10')

def updateTreeNodeBtn(self):
    print('--- updateTreeNodeBtn ---')
    item = self.tree.currentItem()
    item.setText(0, 'updateNode')
    item.setText(1, '20')

def delTreeNodeBtn(self):
    print('--- delTreeNodeBtn ---')
    item = self.tree.currentItem()
    root = self.tree.invisibleRootItem()
    for item in self.tree.selectedItems():
        (item.parent() or root).removeChild(item)