Transactional Operations with google.cloud.ndb

I am using Google Cloud Datastore via the python-ndb library (Python 3). My goal is to transactionally create two entities at once. For example, when a user creates an Account entity, also create a Profile entity, such that if either entity fails to be created, then neither entity should be created.

From the datastore documentation, it can be implemented like this:

from google.cloud import datastore
client = datastore.Client()

def transfer_funds(client, from_key, to_key, amount):
    with client.transaction():
        from_account = client.get(from_key)
        to_account = client.get(to_key)

        from_account["balance"] -= amount
        to_account["balance"] += amount

        client.put_multi([from_account, to_account])

However, there is no example provided by the python-ndb documentation. From chatgpt, I tried something like this:

from google.cloud import ndb
client = ndb.Client()

def create_new_account():
    with client.context():

    @ndb.transactional
    def _transaction():

      account = Account()
      account.put()

      profile = Profile(parent=account.key)
      profile.put()

      return account, profile

    try:
      account, profile = _transaction()
    except Exception as e:
      print('Failed to create account with profile')
      raise e

    return account, profile

However, I get the error:

TypeError: transactional_wrapper() missing 1 required positional argument: 'wrapped'

You're almost there. It should be

    @ndb.transactional()
    def _transaction():

Ran your code and got your error. Then amended it to mine and it went through.

Source - https://github.com/googleapis/python-ndb/blob/main/google/cloud/ndb/_transaction.py#L317