PyConnector

pyconnector: Bridge the gap between Node.JS and Python applications

Both Node.JS and Python have their own unique strengths and weaknesses when it comes to developing applications. This module provides a simple and crude interface to embed and use Python code for number crunching queries.

Installation

Just type npm install pyconnector and you are ready to go.

Usage

Node.JS

Create a new instance of PyConnector class having the desired options.

// minimal.js
const Path = require('path')
const PyConnector = require('pyconnector')

// create connector
var PyAPI = new PyConnector({
  // local port or remote IP:Port string '192.168.0.12:9000'
  endpoint: 24001,
  // pass null or remove option to prevent spawning a child process
  path: Path.join(__dirname, 'minimal.py')
});

// query python resolvers
(async function () {
  console.log('Available Python routes:', await PyAPI.routes())
  console.log('Python version:', await PyAPI.query('pyversion'))
  console.log('Increment ++', await PyAPI.query('increment'))
  console.log('Increment ++', await PyAPI.query('increment', { pass_var: 13 }))

  // kill python process
  PyAPI.end()
})()

Python

Install Python dependencies

pip install nodeconnector argparse

Create minimal.py file

# minimal.py
import sys
import time
import argparse
import nodeconnector

# argument parsing, PyConnector automatically sends this
parser = argparse.ArgumentParser( description = 'Python Exposed API' )
parser.add_argument( '--pynodeport', help = 'PyConnector Node.JS query port', default = 24001 )
args = parser.parse_args()

# create interface
nodeq = nodeconnector.Interface( )

# python version query
def nodeq_version( args, ctx = {} ):
    return ( '%d.%d.%d' % ( sys.version_info[ 0 ], sys.version_info[ 1 ], sys.version_info[ 2 ] ) )

# increment value query
def nodeq_increment( args, ctx = {} ):
    # return value
    ctx[ 'inc' ] += 1
    args[ 'value' ] = ctx[ 'inc' ]

    return args

# queries are executed on a separate thread, a context dict can be used to pass data
nodeq.handle( 'pyversion', nodeq_version )
nodeq.handle( 'increment', nodeq_increment, dict( inc = 0 ) ) 

# launch API
nodeq.listen( port = args.pynodeport ) 

# wait
while( True ):
    time.sleep( 0.001 )

Background

PyConnector is intended to be used for rapid prototyping within POC applications. For production and advanced use cases, its recommended to use this ZeroMQ package, which this module heavily relies upon.

License (MIT)

Copyright (C) 2019 Cristian Dobre