Python selectors

selectors 封装了 select 和 epoll，默认使用 epoll，如果无法使用 epoll 就换成 select
select 和 epoll 为 IO多路复用的方式 <- 点击查看

示例：
socket server

import selectors
import socket

sel = selectors.DefaultSelector()


def accept(sock, mask):
    conn, addr = sock.accept()
    print('accepted', conn, 'from', addr)
    conn.setblocking(False)
    sel.register(conn, selectors.EVENT_READ, read)  # 注册连接


def read(conn, mask):
    data = conn.recv(1024)
    if data:
        print('echoing', repr(data), 'to', conn)
        conn.send(data)
    else:
        print('closing', conn)
        sel.unregister(conn)
        conn.close()


sock = socket.socket()
sock.bind(('localhost', 8001))
sock.listen(100)
sock.setblocking(False)     # 设置非阻塞
sel.register(sock, selectors.EVENT_READ, accept)    # 注册连接

while True:
    events = sel.select()
    for key, mask in events:
        callback = key.data     # 设置回调函数
        callback(key.fileobj, mask)     # 执行回调函数

socket client

import socket

HOST = 'localhost'
PORT = 8001
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
while True:
    msg = bytes(input(">>:"), encoding="utf8")
    s.sendall(msg)
    data = s.recv(1024)
    print('Received', repr(data))

当一个新连接进来时调用 accept，当一个已知连接发送数据时调用 read