Revision as of 15:16, 4 June 2012

Python: Examples

How to write a simple server and client in Python

Simple Server/Client communication, communication data is text.

Server

import SocketServer

class EchoRequestHandler(SocketServer.BaseRequestHandler):
    def setup(self):
        print self.client_address, 'connected!'
        self.request.send('hi ' + str(self.client_address) + '\n')

    def handle(self):
        while 1:
            data = self.request.recv(1024)
            self.request.send(data)
            if data.strip() == 'bye':
                return

    def finish(self):
        print self.client_address, 'disconnected!'
        self.request.send('bye ' + str(self.client_address) + '\n')

#server host is a tuple ('host', port)
server = SocketServer.ThreadingTCPServer(('localhost', 5000), EchoRequestHandler)
server.serve_forever()
 

Client

 
import socket

sock = socket.socket(socket.AF_INET, sock.SOCK_STREAM)
sock.connect(('localhost', 5000))
print sock.recv(1024)
sock.send('bye')
 

How to create a subprocess in a thread with Python

How to call an external command with `Popen`, a subprocess, inside of a thread.

import threading
import subprocess

class MyClass(threading.Thread):
    def __init__(self):
        self.stdout = None
        self.stderr = None
        threading.Thread.__init__(self)

    def run(self):
        p = subprocess.Popen('rsync -av /etc/passwd /tmp'.split(),
                             shell=False,
                             stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE)

        self.stdout, self.stderr = p.communicate()

myclass = MyClass()
myclass.start()
myclass.join()
print myclass.stdout