objectif

Attendre la lisibilité/écriture de sockets/fichiers sans bloquer.

code minimal

import selectors, socket
sel = selectors.DefaultSelector()
a, b = socket.socketpair()
try:
    a.setblocking(False); b.setblocking(False)
    sel.register(a, selectors.EVENT_READ)
    b.send(b"x")
    events = sel.select(timeout=0.1)
    print(any(key.fileobj is a for key, _ in events))  # attendu: True
finally:
    sel.close(); a.close(); b.close()

utilisation

import selectors, socket
sel = selectors.DefaultSelector()
a, b = socket.socketpair()
try:
    sel.register(a, selectors.EVENT_READ, data="tag")
    b.send(b"ok")
    ready = sel.select(0.05)
    print(len(ready) == 1 and ready[0][0].data == "tag")
finally:
    sel.close(); a.close(); b.close()

variante(s) utile(s)

import selectors
print(hasattr(selectors, "DefaultSelector"))

notes

• DefaultSelector choisit epoll/kqueue/poll selon la plate-forme.
• Utilisez setblocking(False) sur les sockets pour un vrai non-bloquant.