UniAnimate/utils/multi_port.py

import socket
from contextlib import closing

def find_free_port():
    """ https://stackoverflow.com/questions/1365265/on-localhost-how-do-i-pick-a-free-port-number """
    with closing(socket.socket(socket.AF_INET, socket.SOCK_STREAM)) as s:
        s.bind(('', 0))
        s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        return str(s.getsockname()[1])