Today, we will talk about how to handle WebSocket requests using the requests-html library in Python. WebSocket is a communication protocol that provides full-duplex communication channels over a single TCP connection, making it suitable for real-time applications.

Installation

First, let’s install the requests-html library using pip:

pip install requests-html

Next, we need to import the necessary modules in our Python script:

from requests_html import AsyncHTMLSession
import asyncio

Making WebSocket Requests

To make WebSocket requests using requests-html, we first need to create an instance of AsyncHTMLSession. This class provides an asyncio-compatible interface for making HTML requests, including WebSocket connections.

session = AsyncHTMLSession()

Next, we use the ws_connect() method to establish a WebSocket connection.

async def connect_websocket(url):
    ws = await session.ws_connect(url)
    return ws

The ws_connect() method takes in the WebSocket URL as a parameter and returns a WebSocket object.

Sending and Receiving Messages

Once we have established a WebSocket connection, we can send and receive messages.

To send a message, we can use the send_text() method of the WebSocket object:

async def send_message(ws, message):
    await ws.send_text(message)

To receive messages, we can use the receive_text() method in a loop:

async def receive_messages(ws):
    async for message in ws:
        print("Received message:", message.text)

Closing the WebSocket Connection

Finally, when we are done with the WebSocket connection, we can close it using the close() method:

async def close_connection(ws):
    await ws.close()

Putting It All Together

Let’s see an example of how to use these methods to make a WebSocket request:

async def main():
    ws = await connect_websocket("wss://echo.websocket.org")
    await send_message(ws, "Hello, World!")
    await receive_messages(ws)
    await close_connection(ws)

# Run the event loop
asyncio.get_event_loop().run_until_complete(main())

In this example, we connect to the WebSocket URL wss://echo.websocket.org, send the message “Hello, World!”, receive any messages sent back from the server, and finally close the WebSocket connection.

Conclusion

In this blog post, we have learned how to handle WebSocket requests using the requests-html library in Python. We covered the basics of establishing a WebSocket connection, sending and receiving messages, and closing the connection. WebSocket provides a powerful mechanism for real-time communication in web applications, and the requests-html library makes it easy to work with in Python.

Remember to always refer to the requests-html documentation for more advanced usage or specific features that might be available. Happy coding!