text: # echo-server.py
  
  import socket
  
  HOST = "127.0.0.1"  # Standard loopback interface address (localhost)
  PORT = 7777  # Port to listen on (non-privileged ports are > 1023)
  
  with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
  	s.bind((HOST, PORT))
  	s.listen()
  	conn, addr = s.accept()
  	with conn:
  		print(f"Connected by {addr}")
  		while True:
  			data = conn.recv(1024)
  			if data == b'end': break
  			elif data == b'': data = b' '
  			conn.sendall(data)
  			print('received:', data)
  