Django on JythonFrank Wierzbicki

frank.wierzbicki@sun.com

Who am I?

• Frank Wierzbicki

• Project lead for Jython

• I work at Sun (Oracle?) on Jython fulltime

What is Jython?

• Python that runs on the JVM

• Compiled to Java bytecodes instead of Python bytecodes

• Call Java code seamlessly from Python code

Jython Status

• Current prod version 2.2 is not useful for Django

• Jython 2.5 beta4 is out

• First RC as early as this Friday

• So production release real-soon-now

Modjy

• Modjy implements WSGI for Jython

• Acts as a bridge to Java Servlets

• integrated into Jython’s core

• This is a big part of how we get Django working.

zxJDBC

• zxJDBC implements DB-API

• integrated into Jython’s core

• Another crucial piece to get Django working.

Jython on Django Status

• Works well with Django 1.0.3 and postgresql

• Other databases in progress: MySQL, Oracle, SQLite, MS SqlServer

• Django 1.1 has some refactorings that Jython will need to catch up on...

Why Jython?

• Massive amounts of Java code out there

• Some really useful Java libs

• Great JVM ecosystem

• Internal Java apps that are not yet exposed to the web

What can I use?

• setuptools

• ez_install

• virtualenv

• pip

• many more pure Python tools

What can’t I use yet?

• c-extensions

• PIL

• ctypes (but we’re working on this one!)

• iPython (working on this too!)

Configure Jython

• Get ez_setup.py

• run “jython ez_setup.py”

• In Jython’s bin directory will be an ez_install that runs from Jython

Installing Django on Jython

• Get 1.0.3+ Django - run “jython setup.py install”

• From http://django-jython.googlecode.com get django-jython-1.0b1.tar.gz, untar it and run “jython setup.py install”

• see the django-jython project on googlecode.com for more detail

Java Platform

• Now takes advantage of Java 5 libraries

• Java 5 concurrency libs: No GIL!

• Use a choice of Java garbage collectors

• Use Java native threads

• -J flag namespace for JVM config

Java Integration

• Jython integrates well with Java

• Java classes and interfaces can be subclassed from Jython

• These subclasses are now “new style” classes.

Example: The Java lib poi can read Excel

Deployment

• run “jython manage.py war --include-java-libs=jdbcdriver.jar”

• This will produce a “war file”

• Copy this war file to the auto-deploy directory for most application servers (like GlassFish)

war format for doj

|-- WEB-INF| |-- lib| `-- lib-python| |-- Lib| |-- django| |-- doj| `-- mysite`-- media

Why Django on Jython?

• Lots of ops departments out there that want to deploy to Java App Servers - “give us a war file”

• They have lots of tools for monitoring, etc

• Jython has a good story for threading and performance - and it’s getting better.

Da Vinci Machine

• JVM gets friendlier to dynamic languages

• On the project plan for JDK 7 -- some of it has already there in a hidden state for JDK6

• Method Handles, Invokedynamic, etc

• Hotspot is one of the world’s best tuned VMs - about to be tuned better for us!

Jython Book due in 2009 from Apress

• Josh Juneau

• Jim Baker

• Leo Soto

• Victor NG

• Frank Wierzbicki

Where to Find Out More

• http://www.jython.org

• http://wiki.python.org/jython

• http://fwierzbicki.blogspot.com

• Twitter: fwierzbicki

• http://www.netbeans.org/features/python/

• https://glassfish.dev.java.net/