How to send a message from client to server in python

Question

I'm reading two programs in Python 2.7.10 with client and server. How can I modify these programs in order to send a message from client to server?

server.py:

#!/usr/bin/python           # This is server.py file

import socket               # Import socket module

s = socket.socket()         # Create a socket object
host = socket.gethostname() # Get local machine name
port = 12345                # Reserve a port for your service.
s.bind((host, port))        # Bind to the port

s.listen(5)                 # Now wait for client connection.
while True:
   c, addr = s.accept()     # Establish connection with client.
   print 'Got connection from', addr
   c.send('Thank you for connecting')
   c.close()                # Close the connection

client.py:

#!/usr/bin/python           # This is client.py file

import socket               # Import socket module

s = socket.socket()         # Create a socket object
host = socket.gethostname() # Get local machine name
port = 80              # Reserve a port for your service.

s.connect((host, port))
print s.recv(1024)
s.close                     # Close the socket when done

Answer 1

TCP sockets are bi-directional. So, after connection, there is no difference between server and client, you only have two ends of a stream:

import socket               # Import socket module

s = socket.socket()         # Create a socket object
s.bind(('0.0.0.0', 12345))        # Bind to the port

s.listen(5)                 # Now wait for client connection.
while True:
   c, addr = s.accept()     # Establish connection with client.
   print 'Got connection from', addr
   print c.recv(1024)
   c.close()                # Close the connection

and the client:

import socket               # Import socket module

s = socket.socket()         # Create a socket object
s.connect(('localhost', 12345))
s.sendall('Here I am!')
s.close()                     # Close the socket when done

Answer 2

The above answer throws an error: TypeError: a bytes-like object is required, not 'str' However, the following code worked for me:

server.py

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
port = 3125
s.bind(('0.0.0.0', port))
print ('Socket binded to port 3125')
s.listen(3)
print ('socket is listening')

while True:
    c, addr = s.accept()
    print ('Got connection from ', addr)
    print (c.recv(1024))
    c.close()

client.py:

import socket

s = socket.socket()
port = 3125
s.connect(('localhost', port))
z = 'Your string'
s.sendall(z.encode())    
s.close()