Python select示例

import select
import socket
import sys
import queue
# Create a TCP/IP
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.setblocking(0)
# Bind the socket to the port
server_address = (‘localhost‘, 10000)
print (sys.stderr, ‘starting up on %s port %s‘ % server_address)
server.bind(server_address)
# Listen for incoming connections
server.listen(5)
# Sockets from which we expect to read
inputs = [ server ]
# Sockets to which we expect to write
outputs = [ ]
# Outgoing message queues (socket:Queue)
message_queues = {}
while inputs:

    # Wait for at least one of the sockets to be ready for processing
    print (sys.stderr, ‘waiting for the next event‘)
    readable, writable, exceptional = select.select(inputs, outputs, inputs)

    # Handle inputs
    for s in readable:

        if s is server:
            # A "readable" socket is ready to accept a connection
            connection, client_address = s.accept()
            print (sys.stderr, ‘  connection from‘, client_address)
            connection.setblocking(0)
            inputs.append(connection)

            # Give the connection a queue for data we want to send
            message_queues[connection] = queue.Queue()

        else:
            data = s.recv(1024)
            if data:
                # A readable client socket has data
                print (sys.stderr, ‘  received "%s" from %s‘ %(data, s.getpeername()))
                message_queues[s].put(data)
                # Add output channel for response
                if s not in outputs:
                    outputs.append(s)

            else:
                # Interpret empty result as closed connection
                print (sys.stderr, ‘  closing‘, client_address)
                # Stop listening for input on the connection
                if s in outputs:
                    outputs.remove(s)
                inputs.remove(s)
                s.close()

                # Remove message queue
                del message_queues[s]

    # Handle outputs
    for s in writable:
        try:
            next_msg = message_queues[s].get_nowait()
        except queue.Empty:
            # No messages waiting so stop checking for writability.
            print (sys.stderr, ‘  ‘, s.getpeername(), ‘queue empty‘)
            outputs.remove(s)
        else:
            print (sys.stderr, ‘  sending "%s" to %s‘ %(next_msg, s.getpeername()))
            s.send(next_msg)

    # Handle "exceptional conditions"
    for s in exceptional:
        print (sys.stderr, ‘exception condition on‘, s.getpeername())
        # Stop listening for input on the connection
        inputs.remove(s)
        if s in outputs:
            outputs.remove(s)
        s.close()

        # Remove message queue
        del message_queues[s]

import socket
import sys
messages = [‘This is the message. ‘,
             ‘It will be sent ‘,
             ‘in parts.‘,
             ]

server_address= (‘localhost‘, 10000)

# Create aTCP/IP socket

socks = [socket.socket(socket.AF_INET, socket.SOCK_STREAM),
          socket.socket(socket.AF_INET,socket.SOCK_STREAM),
          ]

# Connect thesocket to the port where the server is listening

print (sys.stderr, ‘connecting to %s port %s‘ % server_address)
for s in socks:
    s.connect(server_address)
for message in messages:
    # Send messages on both sockets
    for s in socks:
        print (sys.stderr, ‘%s: sending"%s"‘ %(s.getsockname(), message))
        s.send(bytes(message,encoding=‘utf-8‘))
    # Read responses on both sockets

    for s in socks:
        data = s.recv(1024)
        print (sys.stderr, ‘%s: received"%s"‘ %(s.getsockname(), data))
        if not data:
            print (sys.stderr, ‘closingsocket‘, s.getsockname())
            s.close()