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How to send a chatlog of all written chats to a newly joined client using socket programming in Python?

I have written a simple server and client py using UDP. The base is working, however I want that every time a user (client) joins, he would receive a chatlog of everything that has been said.
This is my code until now:
Server:
import socket
import threading
import queue
import pickle
messages = queue.Queue()
clients = []
# AF_INET used for IPv4
# SOCK_DGRAM used for UDP protocol
ip = "localhost"
port = 5555
chatlog=[]
UDPServerSocket = socket.socket(family=socket.AF_INET, type=socket.SOCK_DGRAM)
# binding IP and port
UDPServerSocket.bind((ip, port))
def receive():
while True:
try:
message, addr = UDPServerSocket.recvfrom(1024)
messages.put((message, addr))
chatlog.append((message,addr))
except:
pass
def broadcast():
while True:
while not messages.empty():
message, addr = messages.get()
print(message.decode())
if addr not in clients:
clients.append(addr)
for client in clients:
try:
if message.decode().startswith("SIGNUP_TAG:"):
name = message.decode()[message.decode().index(":") + 1:]
UDPServerSocket.sendto(f"{name} joined!".encode(), client)
if len(chatlog)>0:
sending= pickle.dumps(chatlog)
UDPServerSocket.sendto(sending, client)
else:
pass
else:
UDPServerSocket.sendto(message, client)
except:
clients.remove(client)
t1 = threading.Thread(target=receive)
t2 = threading.Thread(target=broadcast)
t1.start()
t2.start()
And the client
import socket
import threading
import random
client= socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
client.bind(("localhost", random.randint(7000, 8000))) # random port for every client
name = "Henk" #test name
def receive():
while True:
try:
message, _ = client.recvfrom(1024)
print(message.decode())
except:
pass
t= threading.Thread(target= receive)
t.start()
#this gives the server the name of the people who have entered the server
client.sendto(f"SIGNUP_TAG: {name}".encode(), ("localhost", 5555))
while True:
message= input("")
if message=="!q":
exit()
else:
client.sendto(f'[{name}]: {message}'.encode(), ("localhost",5555))
So I am actually a bit stuck on how I will approach this. Shall create a text file where every time that a message is written it gets written on the file as well? Or shall I create some kind of string list/database where every message is stored :/

Python socket problem-ConnectionRefusedError: [WinError 10061]

I wanted to create a server-client chatbox room in python, where multiple clients could send messages in the chat box.
This is the server code
import threading
import socket
#setting up the local host and the local port
host = '127.0.0.1'
port = 9879
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind((host, port)) #hosting the server to the host
server.listen() #server listen to incoming connection
#list for client and their nicknames
clients = []
nicknames = []
#broadcast method to send message to all the clients connected to the server
def broadcast(message):
for client in clients:
client.send(message)
def handle (client):
while True:
try:
message = client.recv(1024)
broadcast(message)
except: #if the connection is lost, discard the client
index = clients.index(client)
clients.remove(client)
client.close()
nickname = nicknames[index]
broadcast(f'{nickname} already left the chat!'.encode('ascii'))
nicknames.remove(nickname)
break
#function to receive connection
def receive():
while True:
client, address = server.accept()
print(f"Conncected with {str(address)}")
client.send('NICKNAME'.encode('ascii'))
nickname = client.recv(1024).decode('ascii')
nicknames.append(nickname)
clients.append(client)
print(f'The nickname of the client is {nickname}')
broadcast(f'{nickname} joined the chat!'.encode('ascii'))
client.send('Connected to the server!'.encode('ascii'))
#making thread for every client
thread = threading.Thread(target = handle, args = (client,))
thread.start()
print("Server is waiting for client...")
and this is the client code
import socket
import threading
#nickname prompt
nickname = input("Input your nickname: ")
client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
#binding the client to the port
client.connect(('127.0.0.1', 9879))
def receive():
while True:
try:
message = client.recv(1024).decode('ascii')
if message == 'NICKNAME':
client.send(nickname.encode('ascii'))
else:
print(message)
except:
print("An error occurred!")
client.close()
break
def write():
while True:
message = f'{nickname}: {input("")}'
client.send(message.encode('ascii'))
#making the thread
receive_thread = threading.Thread(target = receive)
receive_thread.start()
write_thread = threading.Thread(target = write)
write_thread.start()
However, whenever i inputted the nickname in the command prompt there was an error
Traceback (most recent call last):
File "C:\Users\march\Documents\Programming\Pyhton\client.py", line 8, in <module>
client.connect(('127.0.0.1', 9879))
ConnectionRefusedError: [WinError 10061] No connection could be made because the target machine actively refused it
I wonder what's the problem because the port for both server and client are the same and the port is available.

On your server code you're missing a call to the receive function that runs the while loop and puts the server on accept for connections.
The code becomes
import threading
import socket
#setting up the local host and the local port
host = '127.0.0.1'
port = 9879
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind((host, port)) #hosting the server to the host
server.listen() #server listen to incoming connection
#list for client and their nicknames
clients = []
nicknames = []
#broadcast method to send message to all the clients connected to the server
def broadcast(message):
for client in clients:
client.send(message)
def handle (client):
while True:
try:
message = client.recv(1024)
broadcast(message)
except: #if the connection is lost, discard the client
index = clients.index(client)
clients.remove(client)
client.close()
nickname = nicknames[index]
broadcast(f'{nickname} already left the chat!'.encode('ascii'))
nicknames.remove(nickname)
break
#function to receive connection
def receive():
while True:
client, address = server.accept()
print(f"Conncected with {str(address)}")
client.send('NICKNAME'.encode('ascii'))
nickname = client.recv(1024).decode('ascii')
nicknames.append(nickname)
clients.append(client)
print(f'The nickname of the client is {nickname}')
broadcast(f'{nickname} joined the chat!'.encode('ascii'))
client.send('Connected to the server!'.encode('ascii'))
#making thread for every client
thread = threading.Thread(target = handle, args = (client,))
thread.start()
print("Server is waiting for client...")
receive() # runs the function that accepts for incoming connections
The client code should run the write() function on the main thread and not on another one, because it requires input from the stdin. You can change your code as follows in order to run the receiving routine on another thread and your "writing" function on the main one.
import socket
import threading
#nickname prompt
nickname = input("Input your nickname: ")
client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
#binding the client to the port
client.connect(('127.0.0.1', 9879))
def receive():
while True:
try:
message = client.recv(1024).decode('ascii')
if message == 'NICKNAME':
client.send(nickname.encode('ascii'))
else:
print(message)
except:
print("An error occurred!")
client.close()
break
def write():
while True:
message = f'{nickname}: {input("")}'
client.send(message.encode('ascii'))
#making the thread
receive_thread = threading.Thread(target = receive)
receive_thread.start()
# on the main thread
write()
The cause of the Connection refused error was due to the fact that the server code immediately exited since the receive function was never actually called.

Please help me in socket programming in python

Problem while making connection with server.
server side:
import socket
import threading
import sys
ip = "let ip address of server, cant type real one for security purposes, example: 1.2.3.4"
port = 9999
def make_socket(ip, port):
global server
try:
server = socket.socket()
server.bind((ip, port))
except:
make_socket(ip, port)
def handle_client(conn, addr):
print(f"Connected with {addr}\n")
connected = True
while connected:
msg = conn.recv(1024).decode("utf-8")
if msg == "exit()":
connected = False
if len(msg) > 0:
print(f"CLIENT: {msg}")
if connected:
msg = input("You: ")
if len(msg) > 0:
conn.send(msg.encode("utf-8"))
conn.close()
def make_connection():
server.listen(2)
while True:
conn, addr = server.accept()
thread = threading.Thread(target=handle_client, args=(conn, addr))
thread.start()
print(f"ACTIVE CONNECTIONS:{threading.activeCount() - 1}")
print("SERVER INITIATED.")
make_socket(ip, port)
make_connection()
client side:
import socket
ip = "same address as written in server side, example: 1.2.3.4"
port = 9999
client = socket.socket()
client.connect((ip, port))
def send(msg):
message = msg.encode("utf-8")
client.send(message)
run = True
while run:
msg = input("You: ")
if msg == "exit()":
send(msg)
run = False
else:
send(msg)
print(f"Server: {client.recv(100).decode('utf-8')}")
It runs as expected in the same pc.
But when I am running client script and server script in 2 different pcs, they are not connecting. Even though the address is same. I have to type the ip address of server in server.bind and client.connect, right? They both should be same, right?

The IP address you pass to client.connect() should be the IP address of the computer where the server is running (if it's the same computer as where the client is running, you can just pass 127.0.0.1 as that address always means localhost). For the bind() call I recommend passing in '' (i.e. an empty string) as the address, so that your server will accept incoming connections from any active network interface. You only need to pass in an explicit IP address to bind() if you want limit incoming connections to only those coming through the local network card that is associated with the specified IP address.

Socket Messaging Client/Server: Client not sending message

I am trying to create a simple chat program using Python and Socket. The server handles the connection between two clients. Whenever I run the program, for one of the clients, every message after the first one does not send. The message does not even reach the server.
This is on Windows, Python3. I've integrated threading so messages can be sent and received at the same time; however, the problem persists.
Server.py
conns = [] # list that stores both connections
def accept(sk):
while True:
conn, addr = sk.accept()
conns.append(conn)
print(addr, "has connected")
t = threading.Thread(target=accept, args=(sk,))
t.start() #start accept thread
def send(conn):
while True:
message = conn.recv(2048)
print(message)
for conn in conns:
conn.send(message) #sends message to every connection
print("Sent message")
t = threading.Thread(target=send, args=(conn,))
t.start() #start threading for send
Client.py
def recvMessages(s):
while True:
message = s.recv(2048)
print(message)
message = message.decode()
messages.append(message)
os.system("cls")
for message in messages:
print(message)
def sendMessage(s):
while True:
message = input()
message = message.encode()
s.send(message)
s = socket.socket()
host = socket.gethostname()
port = 8080
s.connect((host, port))
messages = []
print("Connected")
connected = True
threading.Thread(target=sendMessage, args=(s,)).start()
threading.Thread(target=recvMessages, args=(s,)).start()
All the messages should be sent from both clients, but one client can never send multiple messages, the other works fine.

Your server code is missing it's socket, and accept is not being run in your example, you also have invalid indentation as James pointed out, next time provide a minimal reproducible example.
I also cleaned up your files a bit, as you followed some bad practice, specifically with broadcasting the messages to all clients "def send" which actually receives, avoid confusing naming :)
in your server code you also sent only to one connection (which in your example doesn't exist) which it should be running the receive and send each time a new message is received
server.py
import socket
import threading
conns = [] # list that stores both connections
def accept(sk):
while True:
conn, addr = sk.accept()
conns.append(conn)
print(addr, "has connected")
# receive from new client
receive_t = threading.Thread(target=receive, args=(conn,))
receive_t.start() # start threading for send
def send(s, msg):
# change message ..
s.send(msg)
def broadcast(msg):
for conn in conns:
send(conn, msg)
def receive(conn):
try:
while True:
message = conn.recv(2048)
if not message: # detects if socket is dead, by testing message
print("client sent Nothing, removing")
conns.remove(conn)
break
broadcast(message) # send to all clients
except ConnectionResetError as e:
print('Could not send must be disconnected ')
conns.remove(conn) # remove dead socket
# added missing socket
sock = socket.socket()
sock.bind(('127.0.0.1', 8080))
sock.listen(1) # needs to bind and listen
t = threading.Thread(target=accept, args=(sock,))
t.start() # start accept thread
client.py
import os
import socket
import threading
messages = []
def recvMessages(s):
while True:
message = s.recv(2048)
message = message.decode()
print('new message= ', message)
messages.append(message)
os.system("cls")
for message in messages:
print(message)
def send_message(s):
while True:
message = input()
message = message.encode()
s.send(message)
s = socket.socket()
host = '127.0.0.1'
port = 8080
s.connect((host, port))
print("Connected")
connected = True
# added missing receive
receive = threading.Thread(target=recvMessages, args=(s,)) # missed receive thread in example
receive.start()
send_message(s)

Persistent socket connection in Lua/Python

I'm trying to create a persistent socket connection between a Lua client and Python server. Effectively a script that'll constantly ping the server with keepalive messages
My current issue is that the socket closes after each connection without a means to reopen it for transmission.
Lua Client:
local HOST, PORT = "localhost", 9999
local socket = require('socket')
-- Create the client and initial connection
client, err = socket.connect(HOST, PORT)
client:setoption('keepalive', true)
-- Attempt to ping the server once a second
start = os.time()
while true do
now = os.time()
if os.difftime(now, start) >= 1 then
data = client:send("Hello World")
-- Receive data from the server and print out everything
s, status, partial = client:receive()
print(data, s, status, partial)
start = now
end
end
Python Server:
import socketserver
class MyTCPHandler(socketserver.BaseRequestHandler):
def handle(self):
self.data = self.request.recv(1024).strip()
print("{} wrote".format(self.client_address[0]))
print(self.data)
print(self.client_address)
# Send back some arbitrary data
self.request.sendall(b'1')
if __name__ == '__main__':
HOST, PORT = "localhost", 9999
# Create a socketserver and serve is forever
with socketserver.TCPServer((HOST, PORT), MyTCPHandler) as server:
server.serve_forever()
The expected result is a keepalive ping every second to ensure the client is still connected to the server.

I ended up finding a solution.
The problem seems to have been with the socketserver library in Python. I switched it to raw sockets and things began working how I wanted them to. From there I created threads to handle the back and forth in the background
Python Server:
import socket, threading
HOST, PORT = "localhost", 9999
# Ensures the connection is still active
def keepalive(conn, addr):
print("Client connected")
with conn:
conn.settimeout(3)
while True:
try:
data = conn.recv(1024)
if not data: break
message = data.split(b',')
if message[0] == b'ping':
conn.sendall(b'pong' + b'\n')
except Exception as e:
break
print("Client disconnected")
# Listens for connections to the server and starts a new keepalive thread
def listenForConnections():
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
sock.bind((HOST, PORT))
while True:
sock.listen()
conn, addr = sock.accept()
t = threading.Thread(target=keepalive, args=(conn, addr))
t.start()
if __name__ == '__main__':
# Starts up the socket server
SERVER = threading.Thread(target=listenForConnections)
SERVER.start()
# Run whatever code after this
The Lua client didn't change in this scenario