NDB Parallel Tasklets

Question

Please take a look at this parallel tasklet code snippet #1.

@ndb.tasklet
def get_data_parallel(e):  
  usr, det = yield (e.user.get_async(),                          
                    MyKind.query(ancestor = e.key).fetch_async())  
  raise ndb.Return((e, usr, det))

If e.user is None this raise an Exception.

I'm trying this snippet #2. However I still get Exception: "TypeError: Expected Future, received : None"

@ndb.tasklet
def get_data_parallel(e):
  usr, det = yield (e.user.get_async() if e.user else None, 
                    MyKind.query(ancestor = e.key).fetch_async())
  raise ndb.Return((e, usr, det))

How can I do something like snippet #2 ? It's possible return future(None) or future('') or something similar ??

Thanks and regards.

Moisés Belchín.

Answer 1

For those interested this thread was answered in Google AppEngine Group:

Google App Engine group discuss

Thanks all.