_google_appengine_ext_ndb.py 文件源码

def encode_ndb_key(key, encoder=None):
    """
    When encountering an L{ndb.Key} instance, find the entity in the datastore
    and encode that.
    """
    klass = ndb.Model._kind_map.get(key.kind())

    referenced_object = _get_by_class_key(
        encoder,
        klass,
        key,
    )

    if not referenced_object:
        encoder.writeElement(None)

        return

    encoder.writeObject(referenced_object)