code: def columns( self ):
          
          output = []
          for c in range(self.columnCount()):
              hitem  = self.horizontalHeaderItem(c)
              text = nativestring(hitem.text())
              if ( not text ):
                  text = nativestring(hitem.toolTip())
              output.append(text)
          return output
docs: Returns the list of column names for this table widget's columns.
          
          :return     [<str>, ..]