IRC connectivity issue in Python

Question

I have a Python script which has an infinite while loop. It joins an IRC channel, does some computation, prints some message, sleeps for 5 minutes, and then repeats. Periodically the scripts errors out with the following:

Traceback (most recent call last):
  File "db_alerts.py", line 65, in <module>
    if data.split()[0].find('PING') != -1:
IndexError: list index out of range

The IRC handle leaves the channel with the following message: (03:00:56 PM) TestBOT left the room (quit: Ping timeout: 121 seconds).

My code is as follows:

import json
import socket
import time

if status:
    env = "prod"
    time_of_last_check = 0
    channelfile = 'irc_channels.json' #File to store channel and password in json format
    channelinfo = open(channelfile,'r').read()
    botnick = json.loads(channelinfo)[env]["nick"]
    network = 'irc.xxxx.com'
    ircsock = socket.socket ( socket.AF_INET, socket.SOCK_STREAM ) 
    ircsock.connect((network, 6667))
    ircsock.send("NICK "+ botnick +"\r\n")
    ircsock.send('USER '+ botnick +' userrxxxxx - :'+botnick +"\r\n")
    time.sleep(2)
    ircsock.send ( 'PRIVMSG NickServ :IDENTIFY zzzzzzzz\r\n')
    for channel,password in json.loads(channelinfo)[env]["channel"].iteritems():
        ircsock.send("JOIN "+ channel + " " + password + "\r\n")
    while 1:
        if time.time() - time_of_last_check > 350:
            localtime = time.asctime( time.localtime(time.time()) )
            print "Last run time :", localtime
            for message,ticket in get_data():
                if str(message) != 'None' and str(ticket) != 'None':
                    for channel,password in json.loads(channelinfo)[env]["channel"].iteritems():
                        if channel == "#X":
                            message = "TEST"
                            ircsock.send('PRIVMSG %s :%s \r\n' % (channel,message))
                            time.sleep(1)
                        else:
                            message1 = "TEST1"
                            ircsock.send('PRIVMSG %s :%s \r\n' % (channel,message1))
                            time.sleep(1)
            data = ircsock.recv (4096)
            if data.split()[0].find('PING') != -1:
                            ircsock.send('PONG ' + data.split()[1] + '\r\n' )
            for message,ticket in get_data1():
                                if str(message) != 'None' and str(ticket) != 'None':
                                        for channel,password in json.loads(channelinfo)[env]["channel"].iteritems():
                                               if channel == "#X":
                            message = "TEST"
                            ircsock.send('PRIVMSG %s :%s \r\n' % (channel,message))
                            time.sleep(1)
                        else:
                            message1 = "TEST1"
                            ircsock.send('PRIVMSG %s :%s \r\n' % (channel,message1))
                                                        time.sleep(1)
            time_of_last_check = time.time()
        data = ircsock.recv (4096)
        if data.split()[0].find('PING') != -1:
            ircsock.send('PONG ' + data.split()[1] + '\r\n' )

Answer 1

When connection is closed (EOF), ircsock.recv(4096) returns an empty string. In turn ''.split() returns empty list. And trying to get the first item from an empty list [][0] raises IndexError.