limitations of django on google app engine?

what things are limited when using django on app engine?

is setup the same or you have to chan开发者_开发问答ge things?

are there many libs/modules that use c?

• You cannot use the entire ORM - Use their custom BigTable API.
• You cannot use the urllib library - Use their custom urlfetch for fetching anything.
• You cannot use the file system - Use their blobstore API.
• There is a time limit for the completion of every request, every db query.
• You cannot use any modules that use C. Memcached, PIL, many other useful libraries out of question.
• You modify your app for their custom authentication, custom caching, custom image-thumbnailing etc.

Essentially, you have to write the whole application to their custom API and infrastructure. All you get from django really is the template engine and forms library and there is no lack of good ones for either of these in Python.

Using django's builtin standards provides you portability between databases, between caching systems, between authentication mechanisms etc. - You typically forgo and get locked into the Appengine's infrastructure when you code for it. There is an effort to make Appengine specifics as one of the backend for each of these, in the project django-nonrel. It also supports ORM queries, but supports specific types of joins only and fails in not-so-easily predictable ways. - The authentication and caching backends seem to be solid.

Django and Appengine is definitely not a match made in heaven. You, the developer should take the heat of their discomfort. If you are looking to host on AppEngine, may I suggest Flask (or bottle) as a development tool and if you are looking for Django as the development tool, may I suggest ep.io (or djangy) as a cloud hosting destination.