old_contents: #!/usr/local/bin/python
  import wx
  app=wx.App()
  win=wx.Frame(None,title='Editor',size=(420,345))
  loadbtn=wx.Button(win,label='Open',pos=(225,5),size=(80,25))
  savebtn=wx.Button(win,label='Save',pos=(315,5),size=(80,25))
  filename=wx.TextCtrl(win,pos=(5,5),size=(210,25))
  contents=wx.TextCtrl(win,pos=(5,35),size=(390,260),
           style=wx.TE_MULTILINE|wx.HSCROLL)
  win.Show()
  app.MainLoop()
  
  
new_contents: #!/usr/local/bin/python
  #import wx
  #app=wx.App()
  #win=wx.Frame(None,title='Editor',size=(420,345))
  #loadbtn=wx.Button(win,label='Open',pos=(225,5),size=(80,25))
  #savebtn=wx.Button(win,label='Save',pos=(315,5),size=(80,25))
  #filename=wx.TextCtrl(win,pos=(5,5),size=(210,25))
  #contents=wx.TextCtrl(win,pos=(5,35),size=(390,260),
  #         style=wx.TE_MULTILINE|wx.HSCROLL)
  #win.Show()
  #app.MainLoop()
  import wx
  
  app=wx.App()
  win=wx.Frame(None,title='Editor',size=(410,335))
  bkg=wx.Panel(win)
  
  loadbtn=wx.Button(bkg,label='Open')
  savebtn=wx.Button(bkg,label='Save')
  filename=wx.TextCtrl(bkg)
  contents=wx.TextCtrl(bkg,style=wx.TE_MULTILINE|wx.HSCROLL)
  
  hbox=wx.BoxSizer()
  hbox.Add(filename,proportion=0,flag=wx.EXPAND)
  hbox.Add(loadbtn,proportion=0,flag=wx.LEFT,border=5)
  hbox.Add(savebtn,proportion=0,flag=wx.LEFT,border=5)
  
  vbox=wx.BoxSizer(wx.VERTICAL)
  vbox.Add(hbox,proportion=0,flag=wx.EXPAND|wx.ALL,border=5)
  vbox.Add(contents,proportion=1,
           flag=wx.EXPAND|wx.LEFT|wx.BOTTOM|wx.RIGHT,border=5)
  
  bkg.SetSizer(vbox)
  win.Show()
  
  app.MainLoop()
  
  
subject: Use relative coordinate.