gistfile1.txt

# A sample writing a BlobProperty to an external file.
# (Note: not a BlobReferenceProperty.)
- model: models.Attachment
  connector: csv
  connector_options:
    encoding: utf-8
    columns: from_header
  property_map:
    - property: __key__
      external_name: ID
      export_transform: datastore.Key.name
    - property: filename
      external_name: filename
    - property: filecontents
      external_name: local_filename
      export_transform:
        transform.blob_to_file('filename', 'AttachmentBlobs')