背景：

实现客户端与服务端交互，由于效率原因，要发送与接收异步，提高效率。

需要多线程，本文用线程池管理。

common代码：

import pickle
import struct
import time


def send_msg(conn, data):
    time.sleep(1)
    msg = pickle.dumps(data)
    msg = struct.pack('>I', len(msg)) + msg
    conn.sendall(msg)
    return data, len(msg)


def recv_from(conn, n):
    data = b''
    handle_len = 0
    while handle_len < n:
        packet = conn.recv(n - handle_len)
        if not packet:
            return None
        handle_len += len(packet)
        data += packet
    return data


def recv_msg(conn):
    struct_msg_len = recv_from(conn, 4)
    if not struct_msg_len:
        return None, 0
    msg_len = struct.unpack('>I', struct_msg_len)[0]
    msg = recv_from(conn, msg_len)
    msg = pickle.loads(msg)
    return msg, msg_len

客户端：

#!/usr/bin/python
# -*- coding: utf-8 -*-

import time
import select
import socket
import threading
from threading import Thread
from concurrent.futures import as_completed
from concurrent.futures import ThreadPoolExecutor

from common import send_msg, recv_msg

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  # 生成socket
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)  # 不经过WAIT_TIME，直接关闭
sock.setblocking(False)  # 设置非阻塞编程

inputs = [sock, ]
executor = ThreadPoolExecutor(max_workers=3)  # 设置线程池最大数量

print('client start!!!')

try:
    sock.connect(("127.0.0.1", 789))
except Exception as e:
    print(e)


def handle_received_data(data):
    print("接收服务端信息:", data)
    time.sleep(1)
    return


def receive_service_data():
    """接收服务端返回的数据并处理"""
    while True:
        try:
            r_list, w_list, e_list = select.select(inputs, [], [], 1)
            for event in r_list:
                data, data_len = recv_msg(event)
                if data:
                    try:
                        executor.submit(handle_received_data, data)
                    except Exception as e:
                        print(threading.current_thread(), threading.active_count())
                        print(e)
                else:
                    print("远程断开连接")
                    inputs.remove(event)
                    exit()
        except OSError as e:
            import traceback
            print(traceback.format_exc())
            print(e)
            exit()


def send_client_data(size=100):
    """发送客户端数据"""
    executors = []
    for i in range(size):
        exe = executor.submit(send_msg, sock, {'data': i})
        executors.append(exe)
    for feature in as_completed(executors):
        try:
            data, data_len = feature.result()
        except Exception as e:
            print(e)
        else:
            print(f"客户端发送数据：{data}, len:{data_len}")


if __name__ == '__main__':
    T1 = time.time()

    # 启动接受服务端数据的线程
    Thread(target=receive_service_data).start()

    # 发送客户端数据
    send_client_data(size=10)
    print('all_time:', time.time() - T1)

服务端：

#!/usr/bin/python
# -*- coding: utf-8 -*-
import time
import socket
import select
import threading
from concurrent.futures import ThreadPoolExecutor

from common import send_msg, recv_msg

sock = socket.socket()
sock.bind(('127.0.0.1', 789))
sock.setblocking(False)
sock.listen()

inputs = [sock, ]
lock = threading.Lock()
executor = ThreadPoolExecutor(max_workers=3)  # 设置线程池最大数量

print('service start!!!')


def handle_received_data(event, data):
    time.sleep(1)
    send_msg(event, data)
    print(f"服务端发送数据：{data}")


while True:
    r_list, w_list, e_list = select.select(inputs, [], [], 1)
    for event in r_list:
        if event == sock:
            print("新的客户端连接")
            new_sock, addresses = event.accept()
            inputs.append(new_sock)
        else:
            data, msg_len = recv_msg(event)
            if data:
                print("接收到客户端信息", data)
                executor.submit(handle_received_data, event, data)
            else:
                print("客户端断开连接")
                inputs.remove(event)

运行结果：

---

参考：

Python select.select 模块通信全过程详解_南淮北安的博客-CSDN博客 

Python标准库socketserver使用线程混入实现异步TCP服务器 

Python中的多路复用 (select、poll 和 epoll) 

 Python实现socket的非阻塞式编程 - 简书

https://www.cnblogs.com/i-honey/p/8078518.html 

 Python多线程RuntimeError: can’t start new thread-Grugsum's blog

python自学成才之路 线程间协作之Semaphore，threading.local() - 腾讯云开发者社区-腾讯云 

Python can‘t start new thread_零之领域的博客-CSDN博客 

python socket sendto函数返回值_他拍了拍你，来这里看这个Socket。_weixin_39982580的博客-CSDN博客 python线程数设置多少_为什么线程数增加超过threading.BoundedSemaphore在python的设置？..._weixin_39808803的博客-CSDN博客

https://www.cnblogs.com/shuopython/p/14943175.html 

Python线程池及其原理和使用（超级详细）