docs: def edges_to_dict_of_dataframes(grid, edges):
      """
      Export edges to DataFrame
  
      Parameters
      ----------
      grid: ding0.Network
      edges: list
          Edges of Ding0.Network graph
  
      Returns
      -------
      edges_dict: dict
      """
      omega = 2 * pi * 50
      srid = int(cfg_ding0.get('geo', 'srid'))
  
      lines = {'line_id': [], 'bus0': [], 'bus1': [], 'x': [], 'r': [],
               's_nom': [], 'length': [], 'cables': [], 'geom': [],
               'grid_id': []}
  
      # iterate over edges and add them one by one
      for edge in edges:
  
          line_name = '_'.join(['MV',
                                str(grid.id_db),
                                'lin',
                                str(edge['branch'].id_db)])
  
          # TODO: find the real cause for being L, C, I_th_max type of Series
          if (isinstance(edge['branch'].type['L'], Series) or
                  isinstance(edge['branch'].type['C'], Series)):
              x = omega * edge['branch'].type['L'].values[0] * 1e-3
          else:
  
              x = omega * edge['branch'].type['L'] * 1e-3
  
          if isinstance(edge['branch'].type['R'], Series):
              r = edge['branch'].type['R'].values[0]
          else:
              r = edge['branch'].type['R']
  
          if (isinstance(edge['branch'].type['I_max_th'], Series) or
                  isinstance(edge['branch'].type['U_n'], Series)):
              s_nom = sqrt(3) * edge['branch'].type['I_max_th'].values[0] * \
                      edge['branch'].type['U_n'].values[0]
          else:
              s_nom = sqrt(3) * edge['branch'].type['I_max_th'] * \
                      edge['branch'].type['U_n']
  
          # get lengths of line
          l = edge['branch'].length / 1e3
  
          lines['line_id'].append(line_name)
          lines['bus0'].append(edge['adj_nodes'][0].pypsa_id)
          lines['bus1'].append(edge['adj_nodes'][1].pypsa_id)
          lines['x'].append(x * l)
          lines['r'].append(r * l)
          lines['s_nom'].append(s_nom)
          lines['length'].append(l)
          lines['cables'].append(3)
          lines['geom'].append(from_shape(
              LineString([edge['adj_nodes'][0].geo_data,
                          edge['adj_nodes'][1].geo_data]),
              srid=srid))
          lines['grid_id'].append(grid.id_db)
  
      return {'Line': DataFrame(lines).set_index('line_id')}