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Python Socket - Server side - Cursor is stuck at conn.receive(1024)

I am new to socket programming. I was able to communicate between 2 system with socket communication. But suddenly started facing this issue. Connection is getting established and accepted but when cursor reaches conn.receive(1024) it is stuck at this point. I am not getting neither data nor any error. Can anyone suggest what is going wrong? What are the possible system settings might affect the code? Not able to figure out whether issue is at server or client side.
import socket
HOST = ''
PORT = 2048
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print('Socket created')
s.bind((HOST, PORT))
print('Socket bind complete')
s.listen(10)
print('Socket now listening')
while True:
conn, addr = s.accept()
# Retrieve message size
data = conn.recv(1024).decode()

I figured out the answer!!!!!!!. Since the client side was in java it was seen that flush() command was not used. Once flush() command added it started working.
Thanks for the hint #mama 🙂

How to connect my server to other machine using socket library in Python?

I am new to socket library and server side programming. I made 2 scripts which runs perfectly on my machine i.e. server.py and client.py. But when i test it on two different computers it doesn't worked.
What i want is to make my server.py file connected to client.py,
where server.py will run on my machine and it will be connected to
client.py on a separate machine at any location in the world.
I just know socket only. But if this problem can be solved by use of other library, then also it will be fine.
Here is my code:
server.py
import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = socket.gethostbyname(socket.gethostname())
port = 12048
s.bind((host, port))
s.listen()
print("Server listening # {}:{}".format(host, port))
while True:
c, addr = s.accept()
print("Got connection from", addr)
c.send(bytes("Thank you", "utf-8"))
client.py
import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = '192.168.1.162' # The IP printed by the server must be set here
port = 12048
s.connect((socket.gethostname(), port))
msg = s.recv(1024)
print(msg.decode("utf-8"))
I don't know how it's possible but if it is then please answer this.
Also, i want to receive files from client.py to my machine. Is it possible in socket or i have to import any other library?
Any help will be appreciated.

The reason the client will only connect to the server running on the same computer is because you are using s.connect((socket.gethostname(), port)) instead of s.connect((host, port)). Your host IP variable is never being used. This error means that the client will be trying to connect to its own hostname, which would be itself, and so that is why it only works on one single computer.
You should modify client.py like this:
import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = '192.168.1.162' # Make sure this is set to the IP of the server
port = 12048
s.connect((host, port))
msg = s.recv(1024)
print(msg.decode("utf-8"))
Now you will be able to connect to a server running on a different computer.

In Client.py you're connecting the socket to socket.gethostname() instead of the ip address of your server. Now, your client is trying to a server that should be running on the same ip as the client. Logically this will work when server and client run on the same ip, but when the client resides on another machine you need to connect to the correct ip address:
s.connect((host, port))
Also, make sure that port is actually open and not blocked by another program. This website helped me open port 7777 on two different laptops and run your edited code on them. You can do the same for port 12048.
Right-click the Start button.
Click Search.
Type Windows Firewall.
Click Windows Firewall.
Click Advanced settings.
Click Inbound Rules in the left frame of the window.
Click New Rule… in the right frame of the window.
Click Port.
Click Next.
Click either TCP or UDP.
Click Specific local ports.
Type a port number. (In this case, we will open port 12048.)
Click Next.
Click Allow the connection.
Click Next.
Click any network types you'd like to allow the connection over.
Click Next.
Type a name for the rule.
Click Finish.
I believe for a socket you have to open the TCP port but if that doesn't work you can make a new rule for the UDP port as well.

How to send socket message when Server has a preset initial response?

I'm making python binds for Blackmagic's Ethernet Control Protocol ( as documented in https://documents.blackmagicdesign.com/UserManuals/HyperDeckManual.pdf?_v=1528269592000 , page 60). Simple socket connection seems to fail however, because every commands gets rejected with the server's greeting.
This protocol documents how software can communicate with certain blackmagic devices, in this case, Blackmagic's hyperdeck, the device runs a TCP server constantly listening on port 9993, on cmd I can simply telnet to it and issue commands, you'd it expect it to be as straightforward in python, however every command gets ignored for the server's greeting message, the device's information. I have been doing socket's for at least 3 months now and i've tried several methods of code, and all seem to fail.
For the most trivial test i've used:
import socket
HOST = "device's ip"
PORT = 9993
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
s.sendall(b'play')
data = s.recv(1024)
print(data)
and a modified version to try to repeat the command:
import socket
import time
HOST = "device's ip"
PORT = 9993
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
s.sendall(b'play')
data = s.recv(1024)
time.sleep(2)
s.sendall(b'play')
It should start video playback, as documented, and as occurs when I issue the command thru telnet, however the command is completely ignored and data always equals to: b'500 connection info:\r\nprotocol version: 1.9\r\nmodel: HyperDeck Studio Mini\r\n\r\n' , the server's greeting message in byte form, it should instead be 200 ok or some sort of error / acknowledged message, as documented.
This is incredibly annoying and i've thought of using subprocess and issuing commands thru cmd as an alternative, but something tells me there's an easier workaround.

Python server client socket

I've tried to connect two computers with a socket in Python and I don't know why it doesn't work. The files are from internet and it compiles for me but without any results.
The server.py:
#!/usr/bin/python
import socket
s = socket.socket()
host = ''
port = 12345
s.bind((host, port))
s.listen(5)
while True:
c, addr = s.accept()
print 'Got connection from', addr
c.send('Thank you for connecting')
c.close()
and the client.py:
#!/usr/bin/python
import socket
s = socket.socket()
host = # here I put the ip of the server's laptop
port = 12345
s.connect((host, port))
print s.recv(1024)
s.close()
What's wrong?

You have to run the server first. Then run the client at the same time with the IP of the server (I used localhost because it was running on one computer, maybe you should try if that works). The code worked fine for me, every time I ran the client, the server printed a message. If it doesn't work for you, maybe your firewall is not letting you open ports.
Just for the future, please always post any error messages you see.
BTW, isn't this the Python Documentation example for sockets?

Cannot run the socket programs correctly in Centos using Python

I'm currently working on with Sockets using Python.
As a starter, I tried copying first the examples given in this (17.2.2. Example) tutorial
I put the client and the server scripts in two different machines (of course)
Now, I want to try if it works, but I'm kind of lost.
I'm thinking of running the server program continuously so that it will keep on receiving the data sent by the client program. However, when I tried to run the Server program, it is giving me this error
socket.error: (99, 'Cannot assign requested address')
and When I tried running the client program, it doesnt give me errors, however, it is printing random data, which is different from what I'm expecting because I sent the String "Hello World", So im expecting that it will receive and print "Hello World"
Shown below is the server program
# Echo server program
import socket
HOST = '192.168.104.112' # Symbolic name meaning all available interfaces
PORT = 50007 # Arbitrary non-privileged port
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
print 'Connected by', addr
while 1:
data = conn.recv(1024)
if not data: break
conn.sendall(data)
conn.close()
and the one below is the client program
# Echo client program
import socket
HOST = '192.168.104.111' # The remote host
PORT = 50007 # The same port as used by the server
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
s.sendall('Hello, world')
data = s.recv(1024)
s.close()
print 'Received', repr(data)
Assuming that the IP of the machine that runs the server program is : 192.168.104.111
while the Client program is : 192.168.104.112
Im not really sure where to get the port number so I just used the port showed in the rpyc in the terminal. how do I get the correct port number anyway?
I know I made a lot of mistakes here. I just don't which part. Could you point me the mistakes that i've done and how to correct them? and how do I run these programs?
BTW, i'm using Centos.

On the server, HOST should be either 0.0.0.0 or the server's own IP address. The server needs to bind its listening port to its own interface(s). The client connects to the server.
Your client program doesn't check for errors. So if it can't connect to the server, things go awry.