# import required modules
import wx
  
  
class MyTree(wx.TreeCtrl):
  
    def __init__(self, parent, id, pos, size, style):
        wx.TreeCtrl.__init__(self, parent, id, pos, size, style)
  
  
class TreePanel(wx.Panel):
  
    def __init__(self, parent):
        wx.Panel.__init__(self, parent)
  
    # create tree control in window
        self.tree = MyTree(self, wx.ID_ANY, wx.DefaultPosition, wx.DefaultSize,
                           wx.TR_HAS_BUTTONS)
  
        # create tree root
        self.root = self.tree.AddRoot('root')
        self.tree.SetPyData(self.root, ('key', 'value'))
  
        # add item to root
        item = self.tree.AppendItem(self.root, "Item")
        item2 = self.tree.AppendItem(self.root, "Item")
  
        # set focused/selected item in control
        self.tree.SetFocusedItem(item)
  
        # print if first visible item is
        # a valid tree item
        if(self.tree.GetFocusedItem().IsOk()):
            print("Valid Item")
            print(self.tree.GetFocusedItem())
        else:
            print("Invalid Item")
  
        sizer = wx.BoxSizer(wx.VERTICAL)
        sizer.Add(self.tree, 100, wx.EXPAND)
        self.SetSizer(sizer)
  
  
class MainFrame(wx.Frame):
  
    def __init__(self):
        wx.Frame.__init__(self, parent=None, title='TreeCtrl Demo')
        panel = TreePanel(self)
        self.Show()
  
  
# Driver Code
if __name__ == '__main__':
    app = wx.App(redirect=False)
    frame = MainFrame()
    app.MainLoop()

Valid Item
<wx._core.TreeItemId object at 0x000001DAED4141F8>