This is a trivial example of a Common Lisp process communicating with a Python process over TCP, using JSON.
The Python process is the "server" and the Lisp process the "client," with the interaction essentially a remote procedure call from Lisp to Python. The Lisp process creates a randomly populated message, containing a string word and a positive integer repeat. It packages them up into a JSON object and sends it, line delimited, to the server. The Python process decodes the JSON and constructs a pair of return values, the first the word repeated repeat times, separated by hyphens, and the second a float, the natural logarithm of the length of the first return value. It packages these up as a JSON object, and sends it, again line delimited, to the Lisp process. Both processes print several lines about what is going on.
To run this
-
first open a terminal window and run
python server.py -
then in a Lisp listener load
client.lispand call(run)
The server code requires Python version 3.7 or later. The Lisp code has only be tested in SBCL version 2.1.10, but
should run in any recent, modern Common Lisp implementation that supports usocket.