code: def to_index_row_dict(df, index_col=None, use_ordered_dict=True):
      
      if index_col:
          index_list = df[index_col]
      else:
          index_list = df.index
  
      columns = df.columns
  
      if use_ordered_dict:
          table = OrderedDict()
      else:
          table = dict()
  
      for ind, tp in zip(index_list, itertuple(df)):
          table[ind] = dict(zip(columns, tp))
  
      return table
docs: Transform data frame to list of dict.
  
      :param index_col: None or str, the column that used as index.
      :param use_ordered_dict: if True, row dict is has same order as df.columns. 
  
      **中文文档**
  
      将dataframe以指定列为key, 转化成以行为视角的dict结构, 提升按行index访问
      的速度。若无指定列, 则使用index。