Basic Python Chat Client

PythonChat.py

import threading
import socket
import sys
from time import gmtime, strftime
from pprint import pprint
host = '' # server
port = 38002 # port
size = 1024 # packet size

s = None
for res in socket.getaddrinfo(host, port, socket.AF_UNSPEC, socket.SOCK_STREAM):
    af, socktype, proto, canonname, sa = res
    try:
        s = socket.socket(af, socktype, proto)
    except OSError as msg:
        s = None
        continue
    try:
        s.connect(sa)
    except OSError as msg:
        s.close()
        s = None
        continue
    break

nickname = ""
if nickname is None or nickname is "":
    print("Please enter a username", end=": ")
    nickname = input()

# if all that worked, we now have two threads we can use
print("Connecting")
s.send(bytearray(nickname,'utf-8'))
loop=True
s.send(bytearray(" \n ",'utf-8')) # to get the data flowing? but why...

def background():
    global size,loop, s
    while loop:
        line = s.recv(size)
        if line.decode("utf-8") is "\n" or line.decode("utf-8") is "":
            pass
        else:
            message = line.decode('utf-8')
            print("< %s" % message)

def send_message(message):
    global s, size, loop
    time = strftime("%Y-%m-%d %H:%M:%S", gmtime())
    s.send(bytearray(message + "\n",'utf8'))

# now threading1 runs regardless of user input
threading1 = threading.Thread(target=background)
threading1.daemon = True
threading1.start()

while True:
    user_input = input()
    if "exit" in user_input:
        s.close()
        sys.exit()
    else:
        send_message(user_input)