At some point in the future I may need to bulk load migration data (i.e. from a CSV). Has anyone had exceptions raised doing the following? Also is there any change in behaviour if the ndb.put_multi() function is used?

from google.appengine.ext import ndb

while True:

    if not id:
        break
    id, name = read_csv_row(readline())
    x = X(parent=ndb.Key('Y','static_id')
    x.id, x.name = id, name
    x.put()

class X(ndb.Model):

    id = StringProperty()
    name = StringProperty()

class Y(ndb.Model):

    pass

def read_csv_row(line):

    """returns tuple"""