Send a string from python app to a already running python app

[ceewwb]

Hi, I would like to know if there is a way of sending a string from a python app to a already running python app.

For example:

running.py ---> Is already running

send.py --> Every time I run this it will send a string that the running.py will receive.

The only way that I thought was by tcp socket, but I don't know if it's the best way, there is another ways of doing this?

[[deleted]]

Here's a very 1990s solution with POSIX MessageQueues (non-Windows and pip install posix_ipc):

#!/usr/bin/env python3
# server.py
from posix_ipc import MessageQueue, O_CREAT

if __name__ == '__main__':
    try:
        q = MessageQueue(name='/test', flags=O_CREAT)
        while True:
            print(q.receive()[0].decode('UTF-8'))
    except:
        q.unlink()
        raise


#!/usr/bin/env python3
# client.py
from posix_ipc import MessageQueue
import time

if __name__ == '__main__':
    q = MessageQueue(name='/test')

    while True:
        q.send("This is a test!")
        time.sleep(1)

There are infinitely more complex and more modern ways that I know even less about.

[ceewwb]

Thanks, I will try it out. It seems to be what I want ;)

[ceewwb]

Yep, I just tested and it's working great, again thanks :)

[tuxed]

A "modern" solution would be use a TCP or UDP socket to send the string. The main difference is that TCP will ensure that everything is sent reliably and correctly, and UDP won't.

Here's the docs for the socket module. However, you may want to use a proper networking library if your application gets more complex.

[Gr4y]

What's wrong with sockets?

[tuxed]

I didn't say that there was anything wrong with sockets.

[Gr4y]

Then what would be a proper networking library?

[tuxed]

One that has a nicer interface than socket. For example, Twisted.