Python implementation of the Socket.IO realtime server.

• Fully compatible with the Javascript socket.io-client library.
• Compatible with Python 2.7 and Python 3.3+.
• Based on Eventlet, enabling large number of clients even on modest hardware.
• Includes a WSGI middleware that integrates Socket.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.

The following application uses Flask to serve the HTML/Javascript to the client:

import socketio
import eventlet
from flask import Flask, render_template

sio = socketio.Server()
app = Flask(__name__)

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

@sio.on('connect', namespace='/chat')
def connect(sid, environ):
    print("connect ", sid)

@sio.on('chat message', namespace='/chat')
def message(sid, data):
    print("message ", data)
    sio.emit(sid, 'reply')

@sio.on('disconnect', namespace='/chat')
def disconnect(sid):
    print('disconnect ', sid)

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

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

• Documentation
• PyPI