convert.py

import sys
import simplejson as json
try:
    import cPickle as pickle
except ImportError:
    import pickle
    

def main(argv):
    try:
        if argv[0] == '--loads':
            json.dump(pickle.load(sys.stdin), sys.stdout)
        elif argv[0] == '--dumps':
            pickle.dump(json.load(sys.stdin), sys.stdout)
    except:
        sys.stdout.write('-1')

if __name__ == '__main__':
    main(sys.argv[1:])

pickle.js

var spawn = require('child_process').spawn;

module.exports.loads = function loads(pickle, callback)
{
    var convert = spawn('python', ['convert.py', '--loads']),
        stdout_buffer = [];
    
    convert.stdout.on('data', function(data)
    {
        stdout_buffer.push(data);
    });
    convert.on('exit', function(code)
    {
        var data = stdout_buffer.join('');
        
        callback(
            data === '-1'
                ? false
                : JSON.parse(data.toString())
        );
    });
    
    convert.stdin.write(pickle);
    convert.stdin.end();
};

module.exports.dumps = function dumps(raw, callback)
{
    var convert = spawn('python', ['convert.py', '--dumps']),
        stdout_buffer = [];
    
    convert.stdout.on('data', function(data)
    {
        stdout_buffer.push(data);
    });
    convert.on('exit', function(code)
    {
        var data = stdout_buffer.join('');
        
        callback(
            data === '-1'
                ? false
                : data
        );
    });
    
    convert.stdin.write(JSON.stringify(raw));
    convert.stdin.end();
};

test.js

var pickle = require('./pickle');

pickle.dumps({"test": true}, function(data)
{
    console.log(data);
});