'Generic, non-detailed view of a snapshot.'

def summary(self, request, snapshot):

    if isinstance(snapshot.metadata, dict):
        metadata = snapshot.metadata
    else:
        metadata = {}
    return {'snapshot': {'id': snapshot.id, 'created_at': snapshot.created_at, 'updated_at': snapshot.updated_at, 'name': snapshot.display_name, 'description': snapshot.display_description, 'volume_id': snapshot.volume_id, 'status': snapshot.status, 'size': snapshot.volume_size, 'metadata': metadata}}
