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

Welcome to Stack Overflow!

I see a few issues:

1. Dictionaries are not supported value types for App Engine properties.
2. You're only storing the last entity; the rest are discarded.
3. You're using a ListProperty, but instead of appending each element of dict_info, you're doing a single append of the entire list.

Since you can't store a raw dictionary inside a property, you need to serialize it to some other format, like JSON or pickle. Here's a revised example using pickle:

from google.appengine.ext import db
import pickle

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

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

db.put(entities)

When you fetch the entity later, you can retrieve your list of dictionaries with pickle.loads(entity.tags).