code: def show_data(self, item):
          
          child, cookie = self.mainview_tree.GetFirstChild(item)
          child_list = []
          while child.IsOk():
              child_list.append(child)
              child, cookie = self.mainview_tree.GetNextChild(item, cookie)
  
          lc = self.nodeview_lc
          lc.DeleteAllItems()
          for i, child in enumerate(child_list):
              text = self.mainview_tree.GetItemText(child)
              try:
                  k, v = [s.strip() for s in text.split(':')]
              except ValueError:
                  k, v = text, '...'
              idx = lc.InsertItem(MAXNROW, v)
              lc.SetItem(idx, 1, k)
docs: show data key-value in ListCtrl for tree item