如何用Python进行网络编程？

# 服务器端代码
import socket

# 创建一个socket对象
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# 绑定到本地地址和端口
server_socket.bind(('localhost', 12345))

# 监听连接
server_socket.listen(5)

print("服务器正在监听...")

while True:
    # 接受客户端连接
    client_socket, addr = server_socket.accept()
    print(f"连接来自 {addr}")

    # 接收数据
    data = client_socket.recv(1024)
    print(f"接收到数据: {data.decode('utf-8')}")

    # 发送响应
    response = "你好，客户端！"
    client_socket.send(response.encode('utf-8'))

    # 关闭连接
    client_socket.close()

# 客户端代码
import socket

# 创建一个socket对象
client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# 连接到服务器
client_socket.connect(('localhost', 12345))

# 发送数据
message = "你好，服务器！"
client_socket.send(message.encode('utf-8'))

# 接收响应
response = client_socket.recv(1024)
print(f"接收到服务器响应: {response.decode('utf-8')}")

# 关闭连接
client_socket.close()

import asyncio

async def handle_client(reader, writer):
    data = await reader.read(100)
    message = data.decode()
    addr = writer.get_extra_info('peername')

    print(f"Received {message} from {addr}")

    response = "Hello, client!"
    writer.write(response.encode())
    await writer.drain()

    writer.close()

async def main():
    server = await asyncio.start_server(handle_client, 'localhost', 12345)

    addr = server.sockets[0].getsockname()
    print(f'Serving on {addr}')

    async with server:
        await server.serve_forever()

asyncio.run(main())