old_contents: # Krzysztof Joachimiak 2017
  # sciquence: Time series & sequences in Python
  #
  # Data structures
  # Author: Krzysztof Joachimiak
  #
  # License: MIT
  
  from collections import OrderedDict
  from operator import itemgetter
  
  
  class MultiDict(OrderedDict):
  
      '''
  
      A dictionary, which allows to get multiple elements at once
  
      Examples
      --------
      >>> md = MultiDict([('a', 1), ('b', 2), ('c', 3)])
      >>> print md[['c', 'a']]
      (3, 1)
  
      '''
  
      def __getitem__(self, item):
          if isinstance(item, list):
              return itemgetter(*item)(self)
          else:
              return super(self.__class__, self).__getitem__(item)
  
new_contents: # Krzysztof Joachimiak 2017
  # sciquence: Time series & sequences in Python
  #
  # Data structures
  # Author: Krzysztof Joachimiak
  #
  # License: MIT
  
  from collections import OrderedDict
  from operator import itemgetter
  
  
  class MultiDict(OrderedDict):
  
      '''
  
      A dictionary, which allows to get multiple elements at once
  
      Examples
      --------
      >>> md = MultiDict([('a', 1), ('b', 2), ('c', 3)])
      >>> print md[['c', 'a']]
      (3, 1)
  
      '''
  
      def __getitem__(self, item):
          if isinstance(item, list):
              return itemgetter(*item)(self)
          else:
              return super(self.__class__, self).__getitem__(item)
  
          
          
  def multi_append(list_of_lists, *elems):
     for l, e in zip(list_of_lists, elems):
         l.append(e)
  
subject: Update data_structures.py