index.js

var binding = require('bindings')('binding.node');
var debug = require('debug')('node-python');
var warn = require('debug')('node-python:warn');
var util = require('util');

function PythonError (message, value) {
  if (arguments[0] instanceof Error) {
    var error = arguments[0];
    this.message = error.message;
    this.stack = error.stack;
    this.value = error.value;
    Error.apply(this, arguments);
  } else {
    Error.call(this, message, value);
  }
}

util.inherits(PythonError, Error);

module.exports.PythonError = PythonError;

var finalized = false;
function pythonFinalized () {
  if (finalized) {
    warn('node-python\'s python interpreter has already been finalized. python code cannot be executed.');
  }
  return finalized;
}

module.exports.eval = function (string) {
  if (pythonFinalized()) throw new PythonError('node-python\'s python interpreter has already been finalized. python code cannot be executed.');
  return binding.eval(string);
}

module.exports.finalize = function () {
  if ( ! pythonFinalized()) {
    binding.finalize();
    finalized = true;
    return finalized;
  }
  return false;
}

var _import = module.exports.import = function (string) {
  if (pythonFinalized()) throw new PythonError('node-python\'s python interpreter has already been finalized. python code cannot be executed.');
  
  var result = null;

  try {
    result = binding.import(string);
  } catch (e) {
    e = new PythonError(e);
    debug(e);
    throw e;
  }

  return result;
}

var os = _import('os');

var pythonPath = os.environ.get('PYTHONPATH');

if (pythonPath === undefined) {
  debug('WARNING: PYTHONPATH environment variable is undefined. This may cause problems finding python modules. see: https://docs.python.org/2/tutorial/modules.html#the-module-search-path');
}