TCP chat room in Python

Question

I have recently started looking into networking with Python. I saw some tutorials about the socket library so I decided to give a "live chat room" idea a go. It works (on Windows, os.system("cls") may be problematic) but was just wanting to see how people could improve upon it

server.py

from socketserver import ThreadingTCPServer, BaseRequestHandler
from threading import Thread
import pickle,time,datetime,os
messages = []
temp = []
os.system("cls")
class Echo(BaseRequestHandler):
 def handle(self):
 self.temp = []
 Thread(target=self.send).start()
 self.username = self.request.recv(8192)
 self.username = self.username.decode()
 print("Got connection from {}:{}".format(self.client_address[0],
 self.client_address[1]))
 while True:
 msg = self.request.recv(8192)
 msg = "[{} {}]: {}".format(datetime.datetime.now().strftime("%H:%M:%S"),
 self.username,
 msg.decode())
 messages.append(msg)
 print(msg)
 if not msg:
 break
 def send(self):
 global temp, messages
 while 1:
 if len(self.temp) != len(messages):
 data_string = pickle.dumps(messages)
 self.request.send(data_string)
 self.temp = [item for item in messages]
if __name__ == "__main__":
 serv = ThreadingTCPServer(("",20000), Echo)
 serv.serve_forever()

client.py

import socket,pickle,os
from threading import Thread
import time
s = socket.socket()
s.connect(('localhost',20000))
def receive():
 while True:
 data = s.recv(8192)
 data = pickle.loads(data)
 os.system("cls")
 for item in data:
 print(item)
username = input("Enter your username: ")
Thread(target=receive).start()
s.send(username.encode())
time.sleep(0.1)
while True:
 msg = input(">>")
 if not msg:
 break
 s.send(msg.encode())
 time.sleep(0.1)

• Graipher: Your indentation within the while True loop seem s to be off. The way it is, it will run for ever.
• Mast: @Graipher A server is usually supposed to run forever. Do you imply the break is not going to have the intended effect?
• mdfst13: @Mast I think he or she was pointing out that the break is not inside the loop with the current indentation. The def send seems wrong too, as it doesn't match def handle.
• cheiffeast: Yes, this is a error on my behalf, my terrible copy and pasting :)
• cheiffeast: I have read some places that using pickle over TCP can be dangerous, if this is true, what other methods can i use to send a list over TCP?

Answer 1

So... handle() gets an incoming connection. Great! What's not so great is that it then spawns self.send in a thread that will never die.

More minorly, I'm not sure why you'd do

 self.username = self.request.recv(8192)
 self.username = self.username.decode()

instead of just

 self.username = self.request.recv(8192).decode()