title: How do you set the editor type for a label in a wxPython PropertyGrid?
body: <p>I figured out how to set the labels on a wxPython PropertyGrid as editable with <code>pg.MakeColumnsEditable(0)</code>, but this only allows editing with a <code>textctrl</code>.  Is there a way to set the editor on the label of a property grid element like we can on the value?  By label I mean the first column of the property grid, and value refers to the second column.</p>
  <p>In the following MWE, I setup a property grid, add two string properties, and then an Enum property.  I then set the labels to be editable with the command above.  What I would really like is the ability to chose labels from a list of choices, like the EnumProperty does with its value.  While the wxPython demo shows several examples of how to create custom editors for values on Property Grids, there are no examples demonstrating how to set a custom editor on a label.</p>
  <p>Can anyone tell me if this is possible, and if so, how it is done?</p>
  <p>Minimal Working Example:</p>
  <pre class="lang-py prettyprint-override"><code>import wx
  import wx.propgrid as wxpg
  
  class MyFrame(wx.Frame):
      def __init__(self, parent, title):
          wx.Frame.__init__(self, parent, title=title, size=(200,100))
          pg = wxpg.PropertyGrid(self)
          pg.Append(wxpg.StringProperty('A', value='1'))
          pg.Append(wxpg.StringProperty('B', value='2'))
          pg.Append(wxpg.EnumProperty('Select', 'Select', ['1', '2', '3']))
          pg.MakeColumnEditable(0)
          self.Show(True)
  
  app = wx.App(False)
  frame = MyFrame(None, 'Property Grid MWE')
  app.MainLoop()
  </code></pre>