Using metadata

info

The code examples in this article is only documented with the Python API Client. While many concepts still apply for the JavaScript API, implementation details might differ.

Key/value metadata can be written to entities using the metadata property and also used to query entities.

The metadata property has a similar interface as a dictionary and keys can be printed using the keys method:

  print(new_sequence['metadata'].keys())
  ['frame_padding', 'focal_length']

or items:

  print(new_sequence['metadata'].items())
  [('frame_padding': '4'), ('focal_length': '70')]

Read existing metadata:

  print(new_sequence['metadata']['frame_padding'])
  '4'

Setting metadata can be done in a few ways where that later one will replace any existing metadata:

  new_sequence['metadata']['frame_padding'] = '5'
  new_sequence['metadata'] = {
    'frame_padding': '4'
  }

Entities can also be queried using metadata:

  session.query(
    'Sequence where metadata any (key is "frame_padding" and value is "4")'
  )