PythonでSocket通信

socket通信

1. socketを作る

• IP: socket.AF_INET
• TCP: socket.AF_INET, socket.SOCK_STREAM
• UDP: socket.AF_INET, socket.SOCK_DGRAM

2. connectionを作る(TCPのみ）

• TCP server: bind, listen, accept
• TCP client: connect

3. 送受信する

• TCP: send, recv
• UDP: sendto, recvfrom

例：TCP通信

googleのページをhttp getで取得

tcp.py

import socket

client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client.connect(("www.google.co.jp",80))
client.send(b"GET / HTTP/1.1\r\nHost: google.com\r\n\r\n")
response = client.recv(4096)
print(response)

例：UDP通信

localserverに"12345"を送信。

udp-client.py

import socket

client = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
client.sendto(b"12345",("127.0.0.1",80))

data, addr = client.recvfrom(4096)
print(data)

例：TCPサーバー

ポート5000で待ち受けて、現在時刻を返す

tcp-server.py

import socket
from datetime import datetime
from time import sleep

s = socket.socket()

port = 5000
s.bind(('', port))

while True:
    print('listening')
    s.listen(5)
    c, addr = s.accept()
    print('receiving')
    print(c.recv(4096))
    while True:
        print('sending')
        now = datetime.now().strftime("%Y/%m/%d %H:%M:%S")
        try:
            c.send(now)
        except:
            break
        sleep(1)
    c.close()
s.close()

tcp-client.py

import socket
from contextlib import closing
import sys

s = socket.socket()

host = sys.argv[1]
port = 5000

#with closing(s):
s.connect((host, port))
s.send("hi")
while True:
    print host, s.recv(4096)