chargen.py

import threading
import socket

CHARS = [chr(i).encode('ascii') for i in range(32, 127)]
NEWLINE = '\n'.encode('ascii')


def server(host='127.0.0.1', port=19):
    def generate(client):
        line = 1

        while True:
            try:
                for i in range(72):
                    char = CHARS[(line + i) % len(CHARS)]
                    client.send(char)

                client.send(NEWLINE)
            except Exception:
                client.close()
                break

            line += 1

    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    sock.bind((host, port))
    sock.listen()

    while True:
        client, _ = sock.accept()
        thread = threading.Thread(target=generate, args=(client,))
        
        thread.start()


server()