python-engineio

Python implementation of the Engine.IO realtime server.

Features

• Fully compatible with the Javascript engine.io-client library, versions 1.5.0 and up.
• Compatible with Python 2.7 and Python 3.3+.
• Supports large number of clients even on modest hardware when used with an asynchronous server based on `asyncio`_(`sanic`_ or aiohttp), eventlet or gevent. For development and testing, any WSGI compliant multi-threaded server can be used.
• Includes a WSGI middleware that integrates Engine.IO traffic with standard WSGI applications.
• Uses an event-based architecture implemented with decorators that hides the details of the protocol.
• Implements HTTP long-polling and WebSocket transports.
• Supports XHR2 and XHR browsers as clients.
• Supports text and binary messages.
• Supports gzip and deflate HTTP compression.
• Configurable CORS responses to avoid cross-origin problems with browsers.

Examples

The following application uses the Eventlet asynchronous server, and includes a small Flask application that serves the HTML/Javascript to the client:

import engineio
import eventlet
import eventlet.wsgi
from flask import Flask, render_template

eio = engineio.Server()
app = Flask(__name__)

@app.route('/')
def index():
    """Serve the client-side application."""
    return render_template('index.html')

@eio.on('connect')
def connect(sid, environ):
    print("connect ", sid)

@eio.on('message')
def message(sid, data):
    print("message ", data)
    eio.send(sid, 'reply')

@eio.on('disconnect')
def disconnect(sid):
    print('disconnect ', sid)

if __name__ == '__main__':
    # wrap Flask application with engineio's middleware
    app = engineio.Middleware(eio, app)

    # deploy as an eventlet WSGI server
    eventlet.wsgi.server(eventlet.listen(('', 8000)), app)

And below is a similar example, coded for asyncio (Python 3.5+ only) with the aiohttp framework:

from aiohttp import web
import engineio

eio = engineio.AsyncServer()
app = web.Application()
eio.attach(app)

async def index(request):
    """Serve the client-side application."""
    with open('index.html') as f:
        return web.Response(text=f.read(), content_type='text/html')

@eio.on('connect')
def connect(sid, environ):
    print("connect ", sid)

@eio.on('message')
async def message(sid, data):
    print("message ", data)
    await eio.send(sid, 'reply')

@eio.on('disconnect')
def disconnect(sid):
    print('disconnect ', sid)

app.router.add_static('/static', 'static')
app.router.add_get('/', index)

if __name__ == '__main__':
    web.run_app(app)

Resources

• Documentation
• PyPI