Open TCP loopback in Python.py

import threading
import socket

# listening to socket with random port
sd = socket.socket(socket.AF_INET)
sd.bind(('127.0.0.1', 0))
ip, port = sd.getsockname()
sd.listen(5)

# connect to socket from "client" side
def connect_as_client(ip, port):
    print ("Connect to: %s:%d" % (ip, port))
    sd = socket.socket(socket.AF_INET)
    sd.connect((ip, port))
    sd.send('hello')
threading.Thread(target=connect_as_client, args=(ip, port)).start()

# accept connection and print data we got as a test
client, addr = sd.accept()
print ("Got data: '%s'" % client.recv(1024))
raw_input()