Python之创建一个session，发送message并且关闭连接

目标
程序按以下顺序接收命令行参数：

IP address
port
message for sending

实现的功能：

Create a new socket.
Connect to a host and a port using the socket.
Send a message from the third command line argument to the host using the socket.
Receive the server’s response.
Print the server’s response.
Close the socket.

代码实现如下：

import socket
import sys

client_socket = socket.socket()
hostname = sys.argv[1]
port = sys.argv[2]
# 地址是一个元组
address = (hostname, port)
client_socket.connect(address)
# 连接成功之后，发送信息
message = sys.argv[3].encode()
client_socket.send(message)
# 接收信息
response = client_socket.recv(port)
response = response.decode()
print(response)

client_socket.close()