code: def export_csv(ekey, dstore):
      
      name = ekey[0] + '.csv'
      try:
          array = dstore[ekey[0]].value
      except AttributeError:
          # this happens if the key correspond to a HDF5 group
          return []  # write a custom exporter in this case
      if len(array.shape) == 1:  # vector
          array = array.reshape((len(array), 1))
      return [write_csv(dstore.export_path(name), array)]
docs: Default csv exporter for arrays stored in the output.hdf5 file
  
      :param ekey: export key
      :param dstore: datastore object
      :returns: a list with the path of the exported file