I've been using pure (slightly tweaked) Django over 3 years and used in running with EC2, some other VPS. However, maintaining the server is a bit pain, and decided to go with google app engine. I've used Django with MongoEngine with mongodb as backend, but seems Google's Data Store (schemaless) is way to go.
So, at this point, I want to do these: 1. Use Google's schemaless nosql database. 2. Use AngularJs for frontend (need to tweak django to work with templating engine). or maybe use Jinja2 for templating (may need tweak...??) 3. Need internationalization (i18n) support -- which django is really great for. 4. I used Django-celery for async tasks, but seems google's app engine has some apis for this.. 5. I heavily used Django's Form to do user input and still will do server-side validations eventhough I validate through js. Is Flask's WTForm good enough to cover my usage?
Now, my question is should I still go with Django or seems "Flask" is bit cooler than Django, would Flask fit better for my purpose? or some other python frameworks? or maybe webapp2?
Both Flask and Django are frameworks that mostly use relational databases. This means that there is no in-built support in either framework for NoSQL databases, which may be a problem given your statment above:
I want to do these: 1. Use Google's schemaless nosql database.
If you wanted to use Flask with a NoSQL database, you'd have to custom code the functionality yourself.