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A request to send or receive data was disallowed because the socket is not connected in Python

I'm trying to make a console chat app in python using socket library.
Whenever I send a message to the server, the server code crashes with the following message:
OSError: [WinError 10057] A request to send or receive data was disallowed because the socket is not connected and (when sending on a datagram socket using a sendto call) no address was supplied
Server code
import socket
HOST = socket.gethostbyname(socket.gethostname()) # get the ip address of PC
PORT = 5050
ADDRESS = (HOST, PORT)
socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
socket.bind(ADDRESS)
while True:
socket.listen()
conn, addr = socket.accept()
print(f"Connected by {addr}")
while True:
data = conn.recv(64)
print(data.decode('utf-8'))
socket.send(data)
Client code
import socket
HOST = socket.gethostbyname(socket.gethostname()) # get the ip address of PC
PORT = 5050
ADDRESS = (HOST, PORT)
socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
socket.connect(ADDRESS)
while True:
msg = input("Enter your message")
socket.send(msg.encode('utf-8'))
data = socket.recv(64)
print(data.decode('utf-8'))
What I am trying to achieve is whenever I send a message to the server, the client script should print the sent message. How can I fix that?

You're attempting to send data to your own server socket. You instead want to send to the client that you accepted.
socket.send(data)
Should be:
conn.send(data)
If you think about it, if you had multiple clients, how would you send data to a specific client? By using the socket that accept gave you.
As a side note, you probably don't want to import the module as socket, and also call your variable socket. It's fine here, but if you were to make a more complicated project, you may accidentally refer to the object when you meant to refer to the module. I'd rename the socket object to sock or server_socket to avoid shadowing.

Python: Socket.error Connection Refused in Unix [Errno 111]

I am trying to send UDP video packets using sockets in Python.
The Server IP address is :192.168.67.14
The Client IP address is 192.168.67.42
The Client and Server can ping each other. Below is the code used for establishing the socket:
Server Side:
import urllib, time, os, m3u8
from socket import *
# Socket initialization
s = socket(AF_INET, SOCK_DGRAM)
host = "192.168.67.42"
port = 5000
buf = 1024
addr = (host, port)
s.connect((host, port))
ts_filenames = []
while True:
playlist = "https://sevenwestmedia01-i.akamaihd.net/hls/live/224853/TEST1/master_lowl.m3u8"
m3u8_obj = m3u8.load(playlist)
ts_segments = m3u8_obj.__dict__.values()[6]
ts_segments_str = str(m3u8_obj.segments)
for line in ts_segments_str.splitlines():
if "https://" in line:
ts_id = line[-20:]
if ts_id not in ts_filenames:
print ts_id
ts_filenames.append(ts_id)
try:
ts_segment = urllib.URLopener()
ts_segment.retrieve(line, ts_id)
except:
pass
f = open(ts_id, "rb")
data = f.read(buf)
while (data):
if (s.sendto(data, addr)):
print "sending ..."
data = f.read(buf)
Client Side
import socket
s = socket.socket()
host = '192.168.67.14'
port = 5000
s.connect((host,port))
print s.recv(1024)
s.close
Exception I get:
Traceback (most recent call last): File "client.py", line 7, in
s.connect((host,port)) File "/usr/lib/python2.7/socket.py", line 228, in meth
return getattr(self._sock,name)(*args) socket.error: [Errno 111] Connection refused
I spent some time looking into this discussion but I still not sure what to modify. Any suggestions please ?

You have multiple problems here. First, by using connect on the server end, you're telling the operating system that you will only be communicating with IP address "192.168.67.42" port 5000. That is probably not what you intended. (A server usually talks to whatever client wants to talk to it.)
Second, by not specifying SOCK_DGRAM in your client, you're getting the default socket type, which is SOCK_STREAM. That means your client is trying to connect to your server on TCP port 80 -- not UDP port 80 (the two namespaces are totally separate).
For a UDP "session", both sides need an IP address and a port number. If you do not bind a port specifically, the operating system will choose one for you quasi-randomly. In order to link up client and server, they must agree on at least one of those.
So a typical UDP server will bind to a well-known port (presumably you intended 5000 for that purpose). Then the client can connect to the server at that port. The code would look something like this (sans error handling):
Server side:
# Create socket
s = socket(AF_INET, SOCK_DGRAM)
# Bind to our well known port (leave address unspecified
# allowing us to receive on any local network address)
s.bind(('', 5000))
# Receive from client (so we know the client's address/port)
buffer, client_addr = s.recvfrom(1024)
# Now we can send to the client
s.sendto(some_buffer, client_addr)
The client is close to what you have, but you should send some data from the client to the server first so that the server knows your address:
s = socket(AF_INET, SOCK_DGRAM)
# Create connection to server (the OS will automatically
# bind a port for the client)
s.connect((host, port))
# Send dummy data to server so it knows our address/port
s.send(b'foo')
buffer = s.recv(1024)
Note that because you have used connect on the client side, you've permanently specified your peer's address and don't need to use recvfrom and sendto.

On the client side, this is wrong:
s = socket.socket()
for receiving UDP packets, you need to create a UDP socket, same as you did on the server side:
s = socket(AF_INET, SOCK_DGRAM)
Also, if you want your client to be able to receive UDP packets you will need to bind() it to port 5000 (connect() is neither necessary nor sufficient for that).

UDP in Jython 2.7

I'm trying to write a python function that sends an UDP message to a remote host and receives a reply, but I have a really hard time understaning how to do this.
I've been looking at thread: Simple Python UDP Server: trouble receiving packets from clients other than localhost
I understand how to send something, but how to send AND receive in the correct sequence?
Thanks in advance.

Please ignore, I got it..
import socket
UDP_IP = "127.0.0.1"
UDP_PORT = 3001
MESSAGE = "asd"
sock = socket.socket(socket.AF_INET, # Internet
socket.SOCK_DGRAM) # UDP
sock.sendto(MESSAGE, (UDP_IP, UDP_PORT))
sock.bind((UDP_IP, UDP_PORT))
while True:
data, addr = sock.recvfrom(1024) # buffer size is 1024 bytes
print "received message:", data

Python UDP socket. blind() + sendto() error

socket.error: [Errno 49] Can't assign requested address
I'm trying to construct a dns message using udp. However, my socket connection doesn't seem to be working for UDP. I am unable to bind and send using the same socket. Is this expected behavior?
I thought this would work since I saw it here:
https://github.com/rthalley/dnspython/blob/master/dns/query.py#L213-L215
UDP.py
import socket
source_address = ('127.0.0.1', 20202)
destination_address = ('8.8.8.8', 53)
data = "Hello, World!"
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
s.bind(source_address)
print 'Sending UDP to {}'.format(destination_address)
s.sendto(data, destination_address)
# listen for response with s.recvfrom(16384)

source_address = ('127.0.0.1', 20202)
You're trying to send from your loopback device. You can't do that, it's local to your machine only. Use one of your external IP addresses, or bind your socket to the wildcard address 0.0.0.0 .

Server send data in python

I'm writing a simple client server app in python, where the client is listening every type of data entering in the specific port, and I want to when receiving a data flow, send back to the connected client (which have a dinamic ip) a string, in this case "001". But when I try to send the message, it fails!
#!/usr/bin/env python
import socket
TCP_IP = '192.168.1.115'
TCP_PORT = 55001
BUFFER_SIZE = 1024
MESSAGE = '01'
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((TCP_IP, TCP_PORT))
s.listen(1)
conn, addr = s.accept()
print ('Connection address:', addr)
while 1:
data = conn.recv(BUFFER_SIZE)
if not data: break
print ('received data:', data)
conn.send(data) # echo
print ('Sending data to client...')
addr change every connection .. i cannot manage this!
s.connect((addr, TCP_PORT))
s.send(MESSAGE)
data = s.recv(BUFFER_SIZE)
s.close()

(Connected stream) sockets are bidirectional, so there's no need to call connect to get a connection to the client—you already have one.
But you want to know why your code fails. And there are at least three problems with it.
First, after you call listen or connect on a socket, you can't call connect again; you will get an exception (EISCONN on POSIX, something equivalent on Windows). You will have to create a new socket.
Second, is client actually binded and listening for a connection on the same port as the server? If not, your connect can't work. If so, the bind will fail if the client and server are on the same machine.
Third, the addr you get back from accept is a (host, port) pair, not just a host. So, as written, you're trying to connect((('192.168.1.115', 12345), 55001)), which obviously isn't going to work.

You are trying to reply to the client using the server listening socket (s). This is only possible in UDP Servers. Since this is a TCP Server you have to use the conn which is crated using s.accept() to communication with remote client.