Serializing NDB model with repeated key property

Question

How can I serialize my model. I can serialize when the key property is not repeated.

The model looks like:

class Properties(ndb.Model):
  propertyID = ndb.StringProperty(required=True)
  propertyParentKey = ndb.KeyProperty()
  propertyItems = ndb.KeyProperty(repeated=True)

I want to do something like

#get all in list
 fetched = model.Properties.query().fetch()

#to a list of dicts
 toSend = [p.to_dict() for p in fetched]

 #Serialize 
  json.dumps(stuff=toSend)

Is it possible to serialize the model somehow? How can I deal with the list of keyproperties?

Answer 1

Why not build your own json friendly to dictionary method? Something like so would probably suffice:

def custom_to_dict(self):
    return {
      'propertyId': self.propertyID,
      'propertyParentKey': self.propertyParentKey.urlsafe(),
      'propertyItems': [key.urlsafe() for key in self.propertyItems]
    }

https://developers.google.com/appengine/docs/python/ndb/keyclass#Key_urlsafe