Jython

This is what I do on windows machines:

For my work I created an easy to install Jython distro with 
only three files:

  - a windows cmd-file
  - jython.jar
  - jythonlib.zip

I don't use an external registry parameter file because I prefer
to set the options in the starter script instead.

No installation procedure is needed. The only condition is to 
locate this 3 files in the same directory. 
The command file looks like this:

>--------- jython.cmd -----------------------------<
@echo off

rem JYTHON_HOME: jython root directory
set JYTHON_HOME="%~dp0."

rem JYTHON_LIBPATH: location of jythonlib.zip
set JYTHON_LIBPATH="%~dp0jythonlib.zip\Lib"

rem JYTHON_PATH: location of jython.jar
set JYTHON_PATH="%~dp0jython.jar"

rem handle args (args may contain spaces)
set ARGS=
:loop
if [%1] == [] goto end
        set ARGS=%ARGS% %1
        shift
        goto loop
:end

rem start a jython interpreter in JVM
java -Dpython.home=%JYTHON_HOME% 
     -Dpython.path=%JYTHON_LIBPATH% 
     -cp %JYTHON_PATH%;%CLASSPATH% 
     org.python.util.jython %ARGS%
>----------------------------------------------<
 (Put the java command line in one single line 
  inside your jython.cmd file)

The pathname to jython.cmd is arbitrary. Spaces as well as special
characters in the pathname are allowed! One exception of this rule I
encountered is the use of the hash characters '#' in the pathname. 
(I have no idea if this is a java or a jython problem)

The %~dp0 trick doesn't work on WIN9X, try out %0\..  or %0\..\ 
instead (I haven't tried it yet). 
And don't forget to use the .bat extension  on WIN9X!

How to build jythonlib.zip:

jythonlib.zip should contain the Lib\ directory of jython. 
For performance reasons the Python modules should be precompiled.
You can precompile the modules in Lib with the 
compileall.compile_dir function.

My jythonlib.zip looks like this:

Archive:  jythonlib.zip
  Length     Date   Time    Name
 --------    ----   ----    ----
     6711  12-06-03 03:36   Lib/anydbm$py.class
     2783  12-06-03 03:36   Lib/anydbm.py
     5659  12-06-03 03:36   Lib/atexit$py.class
     1327  12-06-03 03:36   Lib/atexit.py
     8083  12-06-03 03:36   Lib/base64$py.class
     2065  12-06-03 03:36   Lib/base64.py
        ..........
    34466  12-06-03 03:36   Lib/zipfile$py.class
    25147  12-06-03 03:36   Lib/zipfile.py
     9735  12-06-03 03:36   Lib/zlib$py.class
     3205  12-06-03 03:36   Lib/zlib.py
     6984  12-06-03 03:36   Lib/__future__$py.class
     3509  12-06-03 03:36   Lib/__future__.py
        0  10-05-04 13:11   Lib/
 --------                   -------
  5785342                   460 files

I guess you can build it as a Java jar-file with Java's jar.exe, 
but Winzip does the job for me.

Test your jython.cmd:

Jython 2.2a0 on java1.3.1_02 (JIT: null)
Type "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.path
['', 'C:\\tools\\jython\\.', 'C:\\tools\\jython\\jythonlib.zip\\Lib']


Here is an example for jython skripts that uses the xerces parser and 
th IBM swt toolkit. Of course you can set CLASSPATH in your global
environment, but it may be more convinient for you to set the 
CLASSPATH for the needed Java libs in your starter script.
AND you have to set the '-Djava.library.path' option to tell Java 
where to find the Windows swt.dll:

In this example the files: 
xercesImpl.jar, xml-apis.jar, swt.jar and swt-win32-2133.dll
are located in jython's root directory.
(You may need the full pathnames of your environment)

>--------- jython.cmd -----------------------------<
@echo off

rem JYTHON_HOME: directory where jython lives
set JYTHON_HOME="%~dp0."

rem JYTHON_LIBPATH: location of jythonlib.zip
set JYTHON_LIBPATH="%~dp0jythonlib.zip\Lib"

rem JYTHON_PATH: location of jython.jar
set JYTHON_PATH="%~dp0jython.jar"

rem JYTHON_XERXES: xerces parser: xercesImpl.jar, xml-apis.jar
set JYTHON_XERXES="%~dp0xercesImpl.jar;%~dp0xml-apis.jar"

rem JYTHON_SWT: IBM eclipse swt.jar
set JYTHON_SWT="%~dp0swt.jar"

rem JYTHON_JAVA_PATH: location of additional dlls: swt-win32-2133.dll
set JYTHON_JAVA_PATH=%JYTHON_HOME%

rem handle args (args may contain spaces)
set ARGS=
:loop
if [%1] == [] goto end
        set ARGS=%ARGS% %1
        shift
        goto loop
:end

rem start a jython interpreter in JVM
java -Djava.library.path=%JYTHON_JAVA_PATH% 
     -Dpython.home=%JYTHON_HOME% 
     -Dpython.path=%JYTHON_LIBPATH% 
     -cp %JYTHON_PATH%;%JYTHON_XERXES%;%JYTHON_SWT%;%CLASSPATH% 
     org.python.util.jython %ARGS%
>----------------------------------------------<
 (Put the java command line in one single line 
  inside your jython.cmd file)


If you don't want to use zipped Python modules use:
  set JYTHON_LIBPATH="%~dp0Lib" 
instead.

None of this is really new, but I never found a survey 
for setting up a convenient jython distro.

Regards

Carl

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