import socket

HOST, PORT = '', 8888


def handle_request(request: bytes) -> bytes:
    request_data = request.decode()
    http_response = f"""HTTP/1.1 200 OK\nContent-Type: text/html\n\n{request_data}"""
    return http_response.encode()


def serve_forever():
    # Устанавливаем TCP-соединение
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as listen_socket:
        listen_socket.bind((HOST, PORT))
        listen_socket.listen()
        print('Serving HTTP on port {port} ...'.format(port=PORT))

        while True:
            client_connection, client_address = listen_socket.accept()
            with client_connection:
                request = client_connection.recv(1024)  # Получаем информацию от клиента
                http_response = handle_request(request)
                client_connection.sendall(http_response)


if __name__ == '__main__':
    serve_forever()

with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as listen_socket:
    listen_socket.bind((HOST, PORT))
    listen_socket.listen()

while True:
    client_connection, client_address = listen_socket.accept()
    with client_connection:
      request = client_connection.recv(1024)  # Получаем информацию от клиента
      http_response = handle_request(client_connection)
      client_connection.sendall(http_response)

with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as listen_socket:
    listen_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, True)
    listen_socket.bind((HOST, PORT))
    listen_socket.listen()
    listen_socket.setblocking(False)

read_sockets, write_sockets, error_sockets = select.select(read_file_descr, write_file_descr, exception_file_descr, timeout)

import logging
import selectors
import socket
import sys

HOST, PORT = '', 8000  # Порт сервера

logger = logging.getLogger(__name__)
logger.setLevel(logging.INFO)
logger.addHandler(logging.StreamHandler(stream=sys.stdout))


def new_connection(selector: selectors.BaseSelector, sock: socket.socket):
    new_conn, address = sock.accept()
    logger.info('accepted new_conn from %s', address)
    new_conn.setblocking(False)

    selector.register(new_conn, selectors.EVENT_READ, read_callback)


def read_callback(selector: selectors.BaseSelector, sock: socket.socket):
    data = sock.recv(1024)
    if data:
        sock.send(data)
    else:
        logger.info('closing connection %s', sock)
        selector.unregister(sock)
        sock.close()


def run_iteration(selector: selectors.BaseSelector):
    events = selector.select()
    for key, mask in events:
        callback = key.data
        callback(selector, key.fileobj)


def serve_forever():
    """
    Метод запускает сервер на постоянное прослушивание новых сообщений
    """
    with selectors.SelectSelector() as selector:
        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as server_socket:
            server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, True)
            server_socket.bind((HOST, PORT))
            server_socket.listen()
            server_socket.setblocking(False)
            logger.info('Server started on port %s', PORT)

            selector.register(server_socket, selectors.EVENT_READ, new_connection)

            while True:
                run_iteration(selector)


if __name__ == '__main__':
    serve_forever()

selector.register(server_socket, selectors.EVENT_READ, new_connection)

def run_iteration(selector: selectors.BaseSelector):
    events = selector.select()
    for key, mask in events:
        callback = key.data
        callback(selector, key.fileobj)

python echo_server.py

telnet 127.0.0.1 8000

Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.