Python基于TCP与UDP协议实现Socket通信

TCP协议

server.py

from socket import socket

tcp_server = socket()
tcp_server.bind(('127.0.0.1', 9000))
tcp_server.listen()

conn, addr = tcp_server.accept()

msg = conn.recv(1024)
print(msg)
conn.send(b'hello from server')

conn.close()
tcp_server.close()

client.py

from socket import socket

tcp_client = socket()
tcp_client.connect(('127.0.0.1', 9000))

tcp_client.send(b'hello from client')
msg = tcp_client.recv(1024)
print(msg)

tcp_client.close()

 

UDP协议

server.py

from socket import socket, SOCK_DGRAM

udp_server = socket(type=SOCK_DGRAM)
udp_server.bind(('127.0.0.1', 9000))

msg, client_addr = udp_server.recvfrom(1024)
print(msg)
udp_server.sendto(b'hello from server', client_addr)

udp_server.close()

client.py

from socket import socket, SOCK_DGRAM

udp_client = socket(type=socket.SOCK_DGRAM)

udp_client.sendto(b'hello from client', ('127.0.0.1', 9000))
msg = udp_client.recv(1024)
print(msg)

udp_client.close()

 

socketserver实现TCP协议可并发的server端

from socketserver import BaseRequestHandler, ThreadingTCPServer

class MyServer(BaseRequestHandler):
    def handle(self):  # 自动触发handle方法，self.request 相当于 conn
        msg = self.request.recv(1024).decode('utf-8')
        self.request.send('收到'.encode('utf-8'))

server = ThreadingTCPServer(('127.0.0.1',9000), MyServer)
server.serve_forever()

 

struct模块解决TCP协议的粘包现象

• 先发送报头

  • 报头长度为4个字节，内容是即将发送的报文的字节长度

  • struct模块中的pack方法能够把所有的数字都固定的转换成4字节

• 再发送报文

server.py

import socket
import struct

sk = socket.socket()
sk.bind(('127.0.0.1', 9000))
sk.listen()

conn, _ = sk.accept()

byte_len1 = conn.recv(4)
size1 = struct.unpack('i', byte_len1)[0]
msg1 = conn.recv(size1)
print(msg1)

byte_len2 = conn.recv(4)
size2 = struct.unpack('i', byte_len2)[0]
msg2 = conn.recv(size2)
print(msg2)

conn.close()
sk.close()

client.py

import socket
import struct

sk = socket.socket()
sk.connect(('127.0.0.1', 9000))

msg1 = b'hello'
byte_len1 = struct.pack('i', len(msg1))
sk.send(byte_len1)
sk.send(msg1)

msg2 = b'world'
byte_len2 = struct.pack('i', len(msg2))
sk.send(byte_len2)
sk.send(msg2)

sk.close()