IRC script which sends its own pings without creating any other threads

irc-own-pings.py

#irc script which sends its own pings without creating any other threads

import socket, random
from datetime import datetime

nick = 'testbot-' + hex(random.randint(0, 0xffffff))[2:]
hostport = ('irc.snoonet.org', 6667)
ping_interval_seconds = 30
ping_timeout_seconds = 60

sock = socket.socket()
sock.connect(hostport)
print 'connected'
sock.settimeout(10)
sock.sendall('USER user b c :real\r\n')
sock.sendall('NICK ' + nick + '\r\n')

try:
	recv_buffer = ""
	last_ping = datetime.now()
	waiting_for_pong = False
	while 1:
		try:
			#print 'reading'
			recv_data = sock.recv(4096)
			if not recv_data or len(recv_data) == 0:
				raise EOFError()
			
			recv_buffer += recv_data
			lb = recv_data.find('\n')
			if lb == -1:
				continue
				
			while lb != -1:
				line = recv_buffer[:lb].rstrip()
				recv_buffer = recv_buffer[lb + 1:]
				lb = recv_buffer.find('\n')
				
				print str(datetime.now()) + ' ' + line
				chunks = line.split(' ')
				if chunks[0] == 'PING':
					sock.sendall(line.replace('PING', 'PONG') + '\r\n')
				elif len(chunks) > 1 and chunks[1] == 'PONG':
					print 'server replied to ping'
					last_ping = datetime.now()
					waiting_for_pong = False
		except socket.timeout:
			#print 'timed out'
			
			if waiting_for_pong:
				if (datetime.now() - last_ping).total_seconds() < ping_timeout_seconds:
					continue
				print 'server ping timed out'
				sock.close()
			else:
				if (datetime.now() - last_ping).total_seconds() < ping_interval_seconds:
					continue
				last_ping = datetime.now()
				print 'sending ping to server'
				waiting_for_pong = True
				sock.sendall('PING :hello world\r\n')
except IOError as e:
	print repr(e)
finally:
	try:
		sock.close()
	except IOError:
		pass
		
print 'end'