next_free_port

next_free_port.py

def next_free_port(host, family, proto):
    for res in socket.getaddrinfo(host, '0', family, proto):
        (family, socktype, proto, _, sockaddr) = res

        with socket.socket(family, socktype) as sock:
            sock.bind((sockaddr[0], 0))
            return sock.getsockname()[:2]

print(next_free_port('vodik', socket.AF_INET, socket.SOCK_STREAM))
print(next_free_port('vodik', socket.AF_INET, socket.SOCK_DGRAM))
print(next_free_port('vodik', socket.AF_INET6, socket.SOCK_STREAM))
print(next_free_port('vodik', socket.AF_INET6, socket.SOCK_DGRAM))