Store a list of dictionaries in GAE

Question

I have a list of about 20 objects and for each object I return a list of 10 dictionaries.
I am trying to store the list of 10 dictionaries for each object in the list on

Answer 1

When I deal with data types that are not directly supported by Google App Engine like dictionaries or custom data type, I usually adopt the handy PickleProperty.

from google.appengine.ext import db
import pickle

class PickleProperty(db.Property):
    def get_value_for_datastore(self, model_instance):
        value = getattr(model_instance, self.name, None)
        return pickle.dumps(value)

    def make_value_from_datastore(self, value):
        return pickle.loads(value)

Once declared the PickleProperty class in your commons.py module, you can use it to store your custom data with something like this:

from google.appengine.ext import db
from commons import PickleProperty

class Tw(db.Model):
  tags = PickleProperty()
  ip = db.StringProperty()

entities = []
for city in lst_of_cities:
  dict_info = hw12.twitter(city)
  entity = Tw()
  entity.tags = dict_info
  entity.ip = self.request.remote_addr
  entities.append(entity)

db.put(entities)

To retrieve the data back go with:

entity.tags