Wxpython Python Tutorial

import wx
class TestFrame(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, None, title="tree: misc tests", size=(400,500))
        il = wx.ImageList(16,16)
        self.fldridx = il.Add(wx.ArtProvider.GetBitmap(wx.ART_FOLDER, wx.ART_OTHER, (16,16)))
        self.fldropenidx = il.Add(wx.ArtProvider.GetBitmap(wx.ART_FILE_OPEN,   wx.ART_OTHER, (16,16)))
        self.fileidx = il.Add(wx.ArtProvider.GetBitmap(wx.ART_NORMAL_FILE, wx.ART_OTHER, (16,16)))
        
        self.tree = wx.TreeCtrl(self, style=wx.TR_DEFAULT_STYLE | wx.TR_EDIT_LABELS)
        self.tree.AssignImageList(il)
        root = self.tree.AddRoot("wx.Object")
        self.tree.SetItemPyData(root, None)
        self.tree.SetItemImage(root, self.fldridx,wx.TreeItemIcon_Normal)
        self.tree.SetItemImage(root, self.fldropenidx,wx.TreeItemIcon_Expanded)
        
        tree = ["A","B","C","D","E","F","G","H"]
        self.AddTreeNodes(root, tree)
        self.tree.Expand(root)
        self.Bind(wx.EVT_TREE_ITEM_ACTIVATED, self.OnActivated, self.tree)
        self.Bind(wx.EVT_TREE_BEGIN_LABEL_EDIT, self.OnBeginEdit, self.tree)
            
    def GetItemText(self, item):
        if item:
            return self.tree.GetItemText(item)
        else:
            return ""
        
    def OnActivated(self, evt):
        print "OnActivated:    ", self.GetItemText(evt.GetItem())
    def OnBeginEdit(self, evt):
        print "OnBeginEdit:    ", self.GetItemText(evt.GetItem())
        item = evt.GetItem()
        if item == self.tree.GetRootItem():
            evt.Veto()
            print "*** Edit was vetoed!"
    def AddTreeNodes(self, parentItem, items):
        for item in items:
            if type(item) == str:
                newItem = self.tree.AppendItem(parentItem, item)
                self.tree.SetItemPyData(newItem, None)
                self.tree.SetItemImage(newItem, self.fileidx,wx.TreeItemIcon_Normal)
            else:
                newItem = self.tree.AppendItem(parentItem, item[0])
                self.tree.SetItemPyData(newItem, None)
                self.tree.SetItemImage(newItem, self.fldridx,wx.TreeItemIcon_Normal)
                self.tree.SetItemImage(newItem, self.fldropenidx,wx.TreeItemIcon_Expanded)
   
                self.AddTreeNodes(newItem, item[1])
app = wx.PySimpleApp(redirect=True)
frame = TestFrame()
frame.Show()
app.MainLoop()