wait external process started before testing and kill before exit in teardown in testing cycle.

subprocess-example.py

import os
import time
import socket
import xmlrpclib
import subprocess

here = os.path.dirname(os.path.abspath(__file__))
target = os.path.join(here, 'server.py')
gateway = None


def setup():
    global gateway
    gateway = subprocess.Popen([target])
    while True:
        try:
            sock = socket.create_connection(('localhost', 9000))
            sock.close()
            break
        except:
            time.sleep(0.1)

def test_add():
    proxy = xmlrpclib.ServerProxy('http://localhost:9000')
    assert proxy.add(5, 7) == 12

def teardown():
    global gateway
    gateway.terminate()
    gateway.wait()

if __name__ == '__main__':
    setup()
    try:
        test_add()
    except:
        pass
    teardown()