code: def select_single_column(engine, column):
      
      s = select([column])
      return column.name, [row[0] for row in engine.execute(s)]
docs: Select data from single column.
  
      Example::
  
          >>> select_single_column(engine, table_user.c.id)
          [1, 2, 3]
  
          >>> select_single_column(engine, table_user.c.name)
          ["Alice", "Bob", "Cathy"]