PynamoDB serialize models to json

pynamo_model_serialize_json.py

from pynamodb.models import Model
from pynamodb.attributes import UnicodeAttribute, ListAttribute, MapAttribute
import os
import json


class BaseModel(Model):
    def to_dict(self):
        rval = {}
        for key in self.attribute_values:
            rval[key] = self.__getattribute__(key)
        return rval


class AddressModel(MapAttribute):
    street = UnicodeAttribute()
    city = UnicodeAttribute()


class Person(BaseModel):
    class Meta:
        table_name = os.environ.get('PERSONS_TABLE', 'persons')
    
    id = UnicodeAttribute(hash_key=True)
    addresses = ListAttribute(of=AddressModel)


if not Person.exists():
    Person.create_table(read_capacity_units=1, write_capacity_units=1, wait=True)

p = Person(hash_key='1', range_key=None, addresses=[{'street': 'JohnSt', 'city': 'New York, NYC'}])
print(json.dumps(p.to_dict(), indent=2))