Question

First Model

    class A(db.Model):
      number = db.IntgerProperty()

second Model

class B(db.Model):
   name = db.StringProperty()
   numbers = db.ListProperty(db.Key)

A Model successfully saved.

a = A()
a.number = 90
a.put()

BadValueError: Items in the numbers list must all be Key instances

b = B()
b.name = 'test'
b.numbers = [90]
b.put()

Will you please help? thanks alot.

Answer 1

Edit (based on OP comment): If you want to insert a db.Key you’ll need to provide one.
Calling put() returns a key, so you can use that, e.g.:

a = A()
the_key = a.put()

b = B()
b.name = 'test'
b.numbers = [the_key]
b.put()

---

Old answer before OP clarification:

With db.ListProperty(db.Key) you’re saying you want a list of db.Key instances.
If you want integers, declare your model like this:

class B(db.Model):
   name = db.StringProperty()
   numbers = db.ListProperty(int)
                             ^^^