code: def CreateColumns( self ):
          
          self.SetItemCount(0)
          # clear any current columns...
          for i in range( self.GetColumnCount())[::-1]:
              self.DeleteColumn( i )
          # now create
          for i, column in enumerate(self.columns):
              column.index = i
              self.InsertColumn(i, column.name)
              if not windows or column.targetWidth is None:
                  self.SetColumnWidth(i, wx.LIST_AUTOSIZE)
              else:
                  self.SetColumnWidth(i, column.targetWidth)
docs: Create/recreate our column definitions from current self.columns