Getting Started¶
simple-websocket
includes a collection of WebSocket servers and clients for
Python, including support for both traditional and asynchronous (asyncio)
workflows. The servers are designed to be integrated into larger web
applications if desired.
Installation¶
This package is installed with pip
:
pip install simple-websocket
Server Example #1: Flask¶
The following example shows how to add a WebSocket route to a Flask application.
from flask import Flask, request
from simple_websocket import Server, ConnectionClosed
app = Flask(__name__)
@app.route('/echo', websocket=True)
def echo():
ws = Server.accept(request.environ)
try:
while True:
data = ws.receive()
ws.send(data)
except ConnectionClosed:
pass
return ''
Integration with web applications using other
WSGI frameworks works in a similar way. The
only requirement is to pass the environ
dictionary to the
Server.accept()
method to initiate the WebSocket handshake.
Server Example #2: Aiohttp¶
The following example shows how to add a WebSocket route to a web application built with the aiohttp framework.
from aiohttp import web
from simple_websocket import AioServer, ConnectionClosed
app = web.Application()
async def echo(request):
ws = await AioServer.accept(aiohttp=request)
try:
while True:
data = await ws.receive()
await ws.send(data)
except ConnectionClosed:
pass
return web.Response(text='')
app.add_routes([web.get('/echo', echo)])
if __name__ == '__main__':
web.run_app(app, port=5000)
Server Example #3: ASGI¶
The next server example shows an asynchronous application that supports the ASGI protocol.
from simple_websocket import AioServer, ConnectionClosed
async def echo(scope, receive, send):
ws = await AioServer.accept(asgi=(scope, receive, send))
try:
while True:
data = await ws.receive()
await ws.send(data)
except ConnectionClosed:
pass
Client Example #1: Synchronous¶
The client example that follows can connect to any of the server examples above using a synchronous interface.
from simple_websocket import Client, ConnectionClosed
def main():
ws = Client.connect('ws://localhost:5000/echo')
try:
while True:
data = input('> ')
ws.send(data)
data = ws.receive()
print(f'< {data}')
except (KeyboardInterrupt, EOFError, ConnectionClosed):
ws.close()
if __name__ == '__main__':
main()
Client Example #2: Asynchronous¶
The next client uses Python’s asyncio
framework.
import asyncio
from simple_websocket import AioClient, ConnectionClosed
async def main():
ws = await AioClient.connect('ws://localhost:5000/echo')
try:
while True:
data = input('> ')
await ws.send(data)
data = await ws.receive()
print(f'< {data}')
except (KeyboardInterrupt, EOFError, ConnectionClosed):
await ws.close()
if __name__ == '__main__':
asyncio.run(main())