net.loadbang.jython

This package is an implementation of Python for MaxMSP, using the Jython package under MXJ.

Jython currently implements a slightly old version of Python (2.5; the C version is now at 2.6) so we use the name "jython" in the package to differentiate it from native implementations.

(Although the version of Python implemented by Jython is not quite up-to-date, Jython seems to be something of a standard as an embedded scripting language.)

Unlike the C Python, Jython has full access to the standard Java libraries and any third-party libraries in the classpath, and can interact with the Java class heirarchy in various interesting ways. Jython also comes with an extensive utility library written in Python itself.

For more information on Jython, see the home page.

The prebuilt JAR files are in the distribution, or the library can be built from the enclosed sources using Maven. (For the Maven build, clone and build net.loadbang.scripting first, since our libraries are not yet in a central repository.)

See the README for net.loadbang.lib for installation details.

Jython 2.7

Following some prompting from Nathanaël Lécaudé, I've done a quick test with an alpha release of Jython 2.7 from here. Everything seems to work fine.

2.7 isn't yet available from any Maven repositories, so it'll need to be downloaded manually and installed using the installer above. There's no standalone release, so Max's JAR search directories need to include both jython.jar and Lib (which will be unpacked into cachedir on first launch).

Issues

Some unit tests are currently failing, due perhaps to the thread-based handling of some printing methods. Am investigating. The package seems to be perfectly functional without the print redirection machinery.

We currently cannot differentiate Python's None value from the null value we see for unbound variables, so X = None will have much the same effect as del X when it comes to outputting X. (For what it's worth, the Groovy implementation is similar.)

The package manager seems to print to stderr when it finds new JAR files, so these appear as errors in the Max window. This is benign.

The thread reentrancy issue is fixed: every invocation into an interpreter is done in its own (synchronised) thread.

Documentation

The JavaDocs can be generated from Maven by

    mvn javadoc:javadoc

The documentation is written to target/site/apidocs.

License

Distributed under the GNU General Public License.

Copyright (C) 2012 Nick Rothwell.