socket_server.py

#!/usr/bin/env python3

import socket

IP_ADDR = '0.0.0.0'
TCP_PORT = 9999
BUFFER_SIZE = 1024

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((IP_ADDR, TCP_PORT))
s.listen(1)

conn, addr = s.accept()
print('Connection address:', addr)
while 1:
     data = conn.recv(BUFFER_SIZE)
     if not data: break
     print('Data from client:',data.decode('utf-8'))
     conn.send(data)  # echo
conn.close()