파이썬 소켓 통신

기본 예시)

 

서버

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

server_address = ('localhost', 61001)

s.bind(server_address)

s.listen()

client_s, client_addr = s.accept()
for i in range(10):
    data = client_s.recv(1024)
    data = data.decode()
    print(data)
    
client_s.close()
print('종료')

클라이언트

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_address = ('localhost', 61001)

s.connect(server_address)

while True:

    data = input('')
    if data == 'q':
        break
    data = data.encode()
    s.send(data)

s.close()

 

 

서로 채팅 주고받기 - 보내고 받는 스레드를 만들면 동시에 실행이 가능하다.

예시)

 

서버

import socket
import threading

def Send(sock):
    while True:
        rawdata = input('')
        data = rawdata.encode()
        sock.send(data)
        if rawdata == 'q':
            break
    sock.close()

def Recv(sock):
    while True:
        data = sock.recv(1024)
        if not data:
            break
        data = data.decode()
        print("Client:", data)
        if(data == 'q'):
            break
    sock.close()

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_address = ('localhost', 61001)

s.bind(server_address)

s.listen()

client_socket, client_addr = s.accept()

recvThread = threading.Thread(target=Recv, args=(client_socket,))
sendThread = threading.Thread(target=Send, args=(client_socket,))
recvThread.start()
sendThread.start()
recvThread.join()
sendThread.join()

클라이언트

import socket
import threading

def Send(sock):
    while True:
        rawdata = input('')
        data = rawdata.encode()
        sock.send(data)
        if rawdata == 'q':
            break
    sock.close()

def Recv(sock):
    while True:
        data = sock.recv(1024)
        if not data:
            break
        data = data.decode()
        print("Server:", data)
        if(data == 'q'):
            break
    sock.close()

server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_address = ('localhost', 61001)

server_socket.connect(server_address)

recvThread = threading.Thread(target=Recv, args=(server_socket,))
sendThread = threading.Thread(target=Send, args=(server_socket,))
recvThread.start()
sendThread.start()
recvThread.join()
sendThread.join()

 

논 블로킹 소켓

def Recv(sock):
    sock.setblocking(False)
    while True:
        time.sleep(1)
        try:
            data = sock.recv(1024)
            if not data:
                break
            data = data.decode()
            print("Server:", data)
            if(data == 'q'):
                break
        except BlockingIOError:
            print("아무것도 일어나지 않았다")
    sock.close()

 

논 블로킹 소켓을 사용하려면 socket.setblocking(False)를 하면 된다.

아무것도 받지 않으면 BlockingIOError를 일으키므로 try except가 필요하다.

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참고: https://docs.python.org/ko/3.15/howto/sockets.html#non-blocking-sockets