Question

Why is neither of the following examples working?

class Person(ndb.Model):
   first_name = ndb.StringProperty()
   last_name = ndb.StringProperty()
   city = ndb.StringProperty()
   birth_year = ndb.IntegerProperty()
   height = ndb.IntegerProperty()

  @classmethod
  def get_person(self, _last_name, _max_height):
     a_person = Person.query(
           ndb.AND(
              Person.last_name == _last_name,
              Person. height == _max_height
       ))
      return a_person

The other example replaces Person with self:

@classmethod
  def get_person(self, _last_name, _max_height):
     a_person = self.query(
           ndb.AND(
              self.last_name == _last_name,
              self. height == _max_height
       ))
      return a_person

So basically I want to be able to call the get_person method with last_name and max_height and have it return a person (assume there is only one match). How do I accomplish that?

The calling class/object has the following lines:

my_person = Person.get_person('Doe',7)
if my_person.first_name is None:
   my_person.first_name = 'John'

But the code fails saying my_person does not have attribute first_name (or whatever other attribute I try).

Answer 1

The following works:

@classmethod
def get_person(self, _last_name, _max_height):
 a_person = Person.query(
       ndb.AND(
          Person.last_name == _last_name,
          Person. height == _max_height
   ))
  return a_person.get()