Sample IPC between Idris and a process using Domain Sockets; an improvement would be to have `Client.idr` launch `Server.py` itself.

Bar.idr

module Bar

import System
import System.File

import Data.String

namespace Main
  export
  main : IO ()
  main
    = do str <- getLine
         Right str <- fPutStrLn stdout (trim str) | Left err => printLn err
         exitSuccess

Client.idr

module Client



import System
import System.File

import Data.String

import Network.Socket

namespace Main
  export
  main : IO ()
  main
    = do Right sock <- socket AF_UNIX Stream 0
           | Left err => putStrLn "Error creating \{show err}"

         res <- connect sock (Hostname "/tmp/capable-test.sock") 0

         if not (res == 0)
          then putStrLn "Error connecting \{show res}"
          else do Right res <- send sock "Echo\n"
                    | Left err => putStrLn "Error sending \{show err}"
                  putStrLn "Sent Echo"

                  Right msg <- recvAll sock
                    | Left err => putStrLn "Error receiving \{show err}"
                  putStrLn "Server says: \{msg}"

Server.py

import socket as s
import subprocess
import tempfile

with s.socket(s.AF_UNIX, s.SOCK_STREAM) as sock:
    sock.bind("/tmp/capable-test.sock")
    sock.listen()
    print("Listening")
    conn, addr = sock.accept()
    print("Spawing")
    with conn:
        with subprocess.Popen(
            ["./build/exec/bar"], # yes the actual process is an Idris one...
            stdin =subprocess.PIPE,
            stdout=subprocess.PIPE
        ) as proc:
            i = conn.recv(1024)
#            print("Received")
#            print(i)
            proc.stdin.write(i)
            proc.stdin.flush()
            o = proc.stdout.readline()
#            print("Sending")
#            print(o)
            conn.sendall(o)