How can I parse JSON in Google App Engine?

Nogwater picture Nogwater · Jul 23, 2009 · Viewed 31.3k times · Source

I'd like to parse a JSON string into an object under Google App Engine (python). What do you recommend? Something to encode/stringify would be nice too. Is what you recommend built in, or a library that I have to include in my app? Is it secure? Thanks.

Answer

Brian M. Hunt picture Brian M. Hunt · Jul 23, 2009

Consider using Django's json lib, which is included with GAE.

from django.utils import simplejson as json

# load the object from a string
obj = json.loads( string )

The link above has examples of Django's serializer, and here's the link for simplejson's documentation.

If you're looking at storing Python class instances or objects (as opposed to compositions of lists, strings, numbers, and dictionaries), you probably want to look at pickle.

I hope that helps.

Incidentally, to get Django 1.0 (instead of Django 0.96) running on GAE, you can use the following call in your main.py, per this article:

from google.appengine.dist import use_library
use_library('django', '1.0')

Edit: Native JSON support in Google App Engine 1.6.0 with Python 2.7

As of Google App Engine 1.6.0, you can use the Python 2.7 runtime by adding runtime: python27 in app.yaml, and then you can import the native JSON library with import json.