My simple client crash everytime it tries to connect to my python socket server

Question

My client crash everytime it tries to connect to my python socket server. I dont know why but but my server seams to start up fine then when i start up my client it establishes a connection to the server but it crash direct. Im doing almost as what they say in py socket docs so im wondering if i have missed something or just staring blindly on something easy. Could any one help pls im using python3.4.

server.py

import socket 

host = ''
port = 1010

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
s.bind((host, port)) 
s.listen(1) 
conn, addr = s.accept() 
print ("Connection from", addr) 
while True: 
    databytes = conn.recv(1024)
    if not databytes: break
    print("Recieved: "+(databytes.decode('utf-8')))
    response = input("Reply: ") 
    if response == "exit": 
        break
    conn.sendall(response.encode('utf-8')) 
conn.close()

client.py

import socket 

host = '127.0.0.1'
port = 1010 

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
s.connect((host, port)) 
print("Connected to "+(host)+" on port "+str(port)) 
initialMessage = input("Send: ") 
s.sendall(initialMessage.encode('utf-8'))  

while True: 
 data = s.recv(1024) 
 print("Recieved: "+(data.decode('utf-8')))
 response = input("Reply: ") 
 if response == "exit": 
     break
 s.sendall(response.encode('utf-8')) 
s.close()

Answer 1

There are two issues in your server/client programs.

1. You server has two accept() calls, before the while loop and inside the while loop , this causes the server to actually wait for two connections before it can start receiving any messages from any client.

2. The socket.sendall() function takes in bytes not string , so you need to encode the string using some suitable encoding to convert it to bytes , before sending the data . Also , the function - socket.recv() - returns bytes . So you need to decode the bytes data (using the same encoding you used to encode when sending) , so that you can get the correct string back and it can be printed. A suitable encoding can be - utf-8 - but you can use any encoding of you choice.

An example of encoding a string and using sendall() func -

s.sendall(response.encode('utf-8'))

an example of decoding the string when receiving the data -

databytes = conn.recv(1024)
if not databytes: break
data = databytes.decode('utf-8')

You do not neccessarily need to store the decoded value in another variable, you can also directly call the .decode('utf-8') function when printing the data like - print("Recieved: "+(data.decode('utf-8'))) .