I am using the subprocess module. And using Popen to start the server subprocess.

# create a process for the server to run on
process = Popen("poetry run -vvv python ./app/server.py", cwd="./api", stderr=PIPE, stdin=PIPE, stdout=PIPE)

The script posts some data on the server and when all the response are received i want to close the subprocess.

server.py starts a fastapi server with uvicorn listening on localhost:8000.

I tried using :

• kill()
• terminate()
• send_signal(CTRL_C_EVENT)
• send_signal(SIGINT)
• send_signal(SIGTERM)
• os.kill(process.pid, SIGINT)
• os.kill(process.pid, SIGTERM)
• os.kill(process.pid, SIGKILL)
• process.stdin.write(b’q’) + process.stdin.flush()
• subprocess.call(“taskkill /f /pid {pid}”.format(pid=process.pid))

None of these solution worked. Everytime i need to run these commands to kill the process that is still running.

netstat -a -o -n | findstr 8000 to find the pid of the process, tasklist | findstr pid to assure that
it’s a python console and taskkill /f /pid pid to kill the process.

I call this method at the end of the script. And i noticed that the pid in the error didn’t match the pid i got when running the commands from last paragraph.

def kill_subprocess(subp):
    subp.send_signal(signal.CTRL_C_EVENT)
    subp.terminate()
    if subp.wait() != 0:
        print("subprocess return code = {code}".format(code=subp.returncode))
        raise RuntimeError("subprocess {pid} still running".format(pid=subp.pid))