WhyJython

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Jython, lest you do not know of it, is the most compelling weapon the Java platform has for its survival into the 21st century - SeanMcGrath

Why Jython

There are numerous alternative languages implemented for the Java VM. The following features help to separate Jython from the rest:

  • Dynamic compilation to Java bytecodes - leads to highest possible performance without sacrificing interactivity.

  • Ability to extend existing Java classes in Jython - allows effective use of abstract classes.

  • Optional static compilation - allows creation of applets, servlets, beans, …

  • Bean Properties - make use of Java packages much easier.

  • Python Language - combines remarkable power with very clear syntax. It also supports a full object-oriented programming model which makes it a natural fit for Java’s OO design.

What Does Jython Do Well?

  • Prototyping

  • Java investigation

    • >>> from java.util import Date
    >>> d = Date()
    >>> print d
    Sat Jan 08 16:26:16 CST 2005
    >>> from java.util import Random
    >>> print dir(Random)
    ['__init__', 'nextBoolean', 'nextBytes', 'nextDouble', 'nextFloat',
    'nextGaussian', 'nextInt', 'nextLong', 'seed', 'setSeed']
    >>>

  • Making bean properties accessible

    • >>> print Date().time
    1105500911121

  • Glues together libraries already written in Java

  • Excellent embedded scripting language

Differences - Python & Jython

Python 2.7

  • C

  • Multi-platform

  • Compiles to .pyc

  • Extend with C

  • GIL ^1^

  • Python garbage collection, which mixes ref counting and mark and sweep

Jython 2.7

  • Written mostly in Java, does use Java Native Runtime for C access, but works with security manager restrictions

  • Java 7 or Java 8

  • Compiles to $py.class files

  • Extend with Java or C using JFFI; full CFFI, ctypes, and C Extension API support planned for the future

  • Truly multi-threaded

  • Java garbage collection, including choice of standard Java GCs; but also provides same API as Python 2.7 to observe GC

  1. []Global Interpreter Lock, explained in [http://docs.python.org/api/threads.html Python documentation, chapter 8.1] (1)