python 网络编程 （1）

TCP连接

网络端代码

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import socket,time,threading

def tcplink(sock, addr):
print('Accept new connection from %s:%s...' % addr)
sock.send(b'Welcome!')
while True:
data = sock.recv(1024)
time.sleep(1)
if not data or data.decode('utf-8') == 'exit':
break
sock.send(('Hello, %s!' % data.decode('utf-8')).encode('utf-8'))
sock.close()
print('Connection from %s:%s closed.' % addr)

s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
# 监听端口:
s.bind(('127.0.0.1', 9999))

s.listen(5)
print('Waiting for connection...')

while True:
# 接受一个新连接:
sock, addr = s.accept()
# 创建新线程来处理TCP连接:
t = threading.Thread(target=tcplink, args=(sock, addr))
t.start()

客户端代码

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# 建立连接:
s.connect(('127.0.0.1', 9999))
# 接收欢迎消息:
print(s.recv(1024).decode('utf-8'))
for data in [b'Michael', b'Tracy', b'Sarah']:
# 发送数据:
s.send(data)
print(s.recv(1024).decode('utf-8'))
s.send(b'exit')
s.close()

UDP连接

服务器代码

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)#SOCK_DGRAM 表示UDP
# 绑定端口:
s.bind(('127.0.0.1', 9999))
print('Bind UDP on 9999...')
while True:
# 接收数据:
data, addr = s.recvfrom(1024)
print('Received from %s:%s.' % addr)
s.sendto(b'Hello, %s!' % data, addr)

客户端代码

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
for data in [b'Michael', b'Tracy', b'Sarah']:
# 发送数据:
s.sendto(data, ('127.0.0.1', 9999))
# 接收数据:
print(s.recv(1024).decode('utf-8'))
s.close()