Function / Arguments / Error Help

[Ghosty]

Hello! I'm new to python... so i did a TCP Packet Sniffer to have an idea on how python is on hacking since i wanna to do anti-TCP Packet sniffers etc.
So i got a python code for sniffing ;D great right?...right??

Anyway, i modified it so it can be like beautiful and nit for the user. So i decide to put arguments like:

--sniff-tcp - Sniff TCP packets / Hosts
--sniff-arp - Sniff ARP packets

So i found this module called ArgParse or argparse or whatever xD i imported it and i did the code so i made a function which will start TCP sniffing
if the user puts --sniff-tcp but everytime i do it i get an error which is haunting me cause this error i have saw it ON EACH OF EVERY SCRIPT I DID EVEN COPIED FROM INTERNET...

File "sniffer.py", line 25
try:
^

IndentslError: unindent does not match any outer indentation level

When i see this error i feel like getting a real python and burn it DOWN >:(

So here's my code:

import socket, sys, time, os
from struct import *
from termcolor import colored
from argparse import ArgumentParser

def helpArg():
	print "--sniff-arp"
	print "--sniff-tcp"

parser = ArgumentParser()

parser.add_argument("--sniff-tcp", action=tcpSniffer())

args = parser.parse_args()


#create an INET, STREAMing socket
def tcpSniffer():
	print colored("[+]", 'green') + (" Starting Sniffers...")
	time.sleep(2)
	print colored("[+]", 'green') + (" Creating socket...")
    try:
       s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_TCP)
	except socket.error , msg:
   		print colored("[!]", 'red') + ('Socket could not be created. Error Code : ' + str(msg[0])) + (' Message ' + msg[1])
    	sys.exit()
    
	print colored("[+]", 'green'), ("Getting Ready Spoofers...")
	time.sleep(3)
 
	# receive a packet
	while True:
    	packet = s.recvfrom(65565)
     
    	#packet string from tuple
    	packet = packet[0]
     
    	#take first 20 characters for the ip header
    	ip_header = packet[0:20]
     
    	#now unpack them :)
    	iph = unpack('!BBHHHBBH4s4s' , ip_header)
     
    	version_ihl = iph[0]
    	version = version_ihl >> 4
    	ihl = version_ihl & 0xF
     
    	iph_length = ihl * 4
     
    	ttl = iph[5] 
    	protocol = iph[6]
    	s_addr = socket.inet_ntoa(iph[8]);
    	d_addr = socket.inet_ntoa(iph[9]);
    	hostname2solv = socket.gethostname()
    	host = socket.gethostbyname(hostname2solv)
     
    	print "############################# IP : " +str(s_addr) + " HOST : " +str(hostname2solv) + " #######################"
    	print 'Client Name : ' + str(hostname2solv)
        print 'Version : ' + str(version) 
        print 'IP Header Length : ' + str(ihl)
        print 'TTL : ' + str(ttl) 
        print 'Protocol : ' + str(protocol) 
        print 'Source Address : ' + str(s_addr) 
        print 'Destination Address : ' + str(d_addr)
     
        tcp_header = packet[iph_length:iph_length+20]
     
        #now unpack them :)
        tcph = unpack('!HHLLBBHHH' , tcp_header)
     
        source_port = tcph[0]
    	dest_port = tcph[1]
    	sequence = tcph[2]
    	acknowledgement = tcph[3]
    	doff_reserved = tcph[4]
    	tcph_length = doff_reserved >> 4
     
    	print 'Source Port : ' + str(source_port) 
    	print 'Dest Port : ' + str(dest_port) 
    	print 'Sequence Number : ' + str(sequence) 
		print 'Acknowledgement : ' + str(acknowledgement) 
    	print 'TCP header length : ' + str(tcph_length)
     
   		h_size = iph_length + tcph_length * 4
    	data_size = len(packet) - h_size
     
    	#get data from the packet
    	data = packet[h_size:]
     
    	print 'Data : ' + data
    	print "#######################################################################################"
   		print

Can anyone please help me with this error?
And if anyone could tell me how to do easy and working arguments in python that could be AWESOME!

Lots of love!