A simple IRC client written in Python.

irc.py

#
# [2016-03-14] Challenge #258 [Easy] IRC: Making a Connection
# https://www.reddit.com/r/dailyprogrammer/comments/4ad23z/20160314_challenge_258_easy_irc_making_a/
#

import socket

input = """chat.freenode.net:6667
dude1267
dude1267
John Doe"""

# Parse input.
ping = 'PING '
pong = 'PONG '
lines = input.split('\n')
host = lines[0].split(':')

# Connect.
client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client.connect((host[0], int(host[1])))

# Handshake.
client.send('NICK ' + lines[1] + '\r\n')
client.send('USER ' + lines[2] + ' 0 * :' + lines[3] + '\r\n')

# Output and ping/pong.
while True:
    data = client.recv(1024)
    print(data)

    if data.startswith(ping):
        resp = data.strip(ping);
        client.send(pong + resp)
        print(pong + resp)

https://gist.github.com/vardrop/b543e2bb85b0c24c66765cb142729f20