Django on Jython Tips

February 16, 2010

I'm using Django on Jython so that I can deploy my app in Tomcat without needing to install a python runtime. This is for a packaged app, so not adding extra dependencies is good.


I installed Jython 2.5.1.

I then setup a project in Eclipse (using pydev) with django 1.1.1 in it, and django-jython 1.1.1 (the doj package).

Building a WAR File

You need to have 'doj' in the your application's INSTALLED_APPLICATIONS

Once that is done, you can use python war to create a standalone war file.

MEDIA_URL problem

I got this error:

OSError: [Errno 0] couldn't make directory: 'c:\\docume~1\\user\\locals~1\\temp\\tmp1zzcc7\\app\\http:localhost:8000'

This was caused by the fact that my MEDIA_URL was set to 'http://localhost:8000/site_media/'. I fixed this problem by changing it to be just /site_media

MEDIA_URL = '/site_media/'

and the WAR file now creates fine. You need to remember to use {{MEDIA_URL}} in HTML templates rather than hardcoded /site_media.


I got the error 'DatabaseWrapper' object has no attribute 'queries' at runtime. Here are the database settings I was using:

DATABASE_ENGINE = ''           
DATABASE_NAME = ''             
DATABASE_USER = ''             
DATABASE_HOST = ''            

Even though I wasn't using a database connection from this app, I needed to set a database engine:

DATABASE_ENGINE = 'doj.backends.zxjdbc.postgresql'


I had a problem submitting forms. It was redirecting to / rather than to where I expected. The problem was because I was using action="." in my form tag. action="" fixed the problem.

Tags: python jython django