jPython

Sample project for calling Python from jBASE 5

Introduction

This is a demo project to demonstrate how to call Python routines from jBASE. It was written/built against Python 3.6 (though other versions may also work).

The project builds a shared library (libjpython) and a test program (callpython_test).

Requirements

jBASE 5 >

Python 3.x (tested with 3.6m)

Building

Linux

make

If you wish to build against a specific maj.min release of Python (e.g. 3.7):

make pythonMaj=3 pythonMin=7

Running the Sample

Build the shared library (see Building)

Point your JBCOBJECTLIST to the location of the shared lib.

Alternatively sudo cp lib/* $JBCRELEASEDIR/lib

export JBCOBJECTLIST=`pwd`/lib:$JBCOBJECTLIST

Depending on your set up you may need to point LD_LIBRARY_PATH to the location of Python's shared library.

The following is specific to the version of Python installed:

export LD_LIBRARY_PATH=/opt/rh/rh-python36/root/usr/lib64:$JBCRELEASEDIR/lib

Now you should be able to run:

bin/callpython_test 45.4157 122.7163 33.9890 151.1393
Distance between 45.4157/122.7163 and 33.9890/151.1393 is 2726.361341

Notes on the jabba syntax

The examples were written prior to the JVAR macro (which makes the language transition between C and jBC vars relatively painless).

Instead the #VARAPPEND directive is used throughout.

Future updates will be targeted to 5.7.6> using JVAR.