def __str__(self):
    """Returns the string representation of this reader.

    Returns:
      string blobkey:[start file num, end file num]:current offset.
    """
    return "blobstore.BlobKey(%r):[%d, %d]:%d" % (
        self._blob_key, self._start_file_index, self._end_file_index,
        self._next_offset())
Returns the string representation of this reader.

    Returns:
      string blobkey:[start file num, end file num]:current offset.
    
mapreduce/input_readers.py