code: def combineColumns(cols):
      'Return Column object formed by joining fields in given columns.'
      return Column("+".join(c.name for c in cols),
                    getter=lambda col,row,cols=cols,ch=' ': ch.join(c.getDisplayValue(row) for c in cols)f combineColumns(cols):
      'Return Column object formed by joining fields in given columns.'
      return Column("+".join(c.name for c in cols),
                    getter=lambda col,row,cols=cols,ch=' ': ch.join(c.getDisplayValue(row) for c in cols))
docs: Return Column object formed by joining fields in given columns.