ndb/db to dict

to_dict.py

import datetime
import time

from google.appengine.ext import db
from google.appengine.ext import ndb


def to_dict(model):
    """Convert a db or ndb entity to a json-serializable dict."""
    output = {}

    for key, prop in model._properties.iteritems():
        value = getattr(model, key)

        if value is None or isinstance(value, SERIALIZABLE_TYPES):
            output[key] = value
        elif isinstance(value, datetime.date):
            # Convert date/datetime to unix timestamp
            output[key] = time.mktime(value.utctimetuple())
        elif isinstance(value, (db.Key, ndb.Key)):
            output[key] = value.id()
        elif isinstance(value, (db.Model, ndb.Model)):
            output[key] = to_dict(value)
        else:
            raise ValueError('Cannot encode ' + repr(prop))

    return output