How to open a WebSocket connection?

To open a WebSocket connection on the client side in Python, you can use the websockets library.

import asyncio
import websockets

async def connect_websocket():
    uri = "ws://localhost:8765"  # WebSocket server address
    async with websockets.connect(uri) as websocket:
        print("WebSocket connection opened.")
        # You can send and receive messages here

if __name__ == "__main__":
    asyncio.run(connect_websocket())

On the server side, also using websockets:

import asyncio
import websockets

async def handle_client(websocket, path):
    print(f"Client connected from {websocket.remote_address}")
    # You can process messages from the client here

async def start_server():
    start_server = websockets.serve(handle_client, "localhost", 8765)
    print("WebSocket server started on ws://localhost:8765")
    await start_server.serve_forever()

if __name__ == "__main__":
    asyncio.run(start_server())

Main steps:

1. Import the library: import websockets.
2. Specify the address: WebSocket server URI (ws://... or wss://...).
3. Create a connection: Use websockets.connect() on the client or websockets.serve() on the server. They are asynchronous functions and are usually used with async with for automatic connection closing.
4. Handle events: After establishing the connection, you can send and receive messages asynchronously.

Alternatives:

• websocket-client: Client library not based on asyncio.
• autobahn|python: Older library supporting both client and server.

The choice depends on project requirements (asynchronous, features, performance). For modern async applications, websockets is recommended.