old_contents: import six
  
  
  class DataIterator(six.Iterator):
      """An iterator over data, representing a single epoch.
  
      Parameters
      ----------
      data_stream : :class:`DataStream` or :class:`Transformer`
          The data stream over which to iterate.
      request_iterator : iterator
          An iterator which returns the request to pass to the data stream
          for each step.
  
      """
      def __init__(self, data_stream, request_iterator=None, as_dict=False):
          self.data_stream = data_stream
          self.request_iterator = request_iterator
          self.as_dict = as_dict
  
      def __iter__(self):
          return self
  
      def __next__(self):
          if self.request_iterator is not None:
              data = self.data_stream.get_data(next(self.request_iterator))
          else:
              data = self.data_stream.get_data()
          if self.as_dict:
              return dict(zip(self.data_stream.sources, data))
          else:
              return data
  
new_contents: import six
  
  
  class DataIterator(six.Iterator):
      """An iterator over data, representing a single epoch.
  
      Parameters
      ----------
      data_stream : :class:`DataStream` or :class:`Transformer`
          The data stream over which to iterate.
      request_iterator : iterator
          An iterator which returns the request to pass to the data stream
          for each step.
      as_dict : bool, optional
          If `True`, return dictionaries mapping source names to data
          from each source. If `False` (default), return tuples in the
          same order as `data_stream.sources`.
  
      """
      def __init__(self, data_stream, request_iterator=None, as_dict=False):
          self.data_stream = data_stream
          self.request_iterator = request_iterator
          self.as_dict = as_dict
  
      def __iter__(self):
          return self
  
      def __next__(self):
          if self.request_iterator is not None:
              data = self.data_stream.get_data(next(self.request_iterator))
          else:
              data = self.data_stream.get_data()
          if self.as_dict:
              return dict(zip(self.data_stream.sources, data))
          else:
              return data
  
subject: Document DataIterator 'as_dict' argument.