Data analysis of wireshark data (pcap)

#-*-coding:utf-8-*-

import dpkt, socket
import string
import binascii
import sys

# main function
defmain(filename):
    pcr=dpkt.pcap.Reader(open(filename, 'rb')))
    # Number of packets
    packet_count = 0

    # packet processing
    forts, bufin pcr:
        packet_count + = 1
        try:
            eth=dpkt.ethernet.Ethernet(buf)
        except:
            continue

        # For IP data:
        if type(eth.data) == dpkt.ip.IP:
            ip=eth.data
            ipheader (ip)
            # TCP data
            if type(ip.data) == dpkt.tcp.TCP:
                tcp = ip.data
                # Payload is not 0
                iflen(tcp.data)!=0:
                    thex = binascii.b2a_hex(tcp.data)
                    payload (thex)
            # UDP data
            elif type (ip.data) == dpkt.udp.UDP:
                udp = ip.data
                # Payload is not 0
                iflen(udp.data)!=0:
                    uhex=binascii.b2a_hex(udp.data)
                    payload(uhex)
            # ICMP data
            elif type (ip.data) == dpkt.icmp.ICMP:
                icmp = ip.data
                # Payload is not 0
                iflen(icmp.data)!=0:
                    ihex=binascii.hexlify(str(icmp.data))
                    payload (ihex [8:])

    print("End of process:", packet_count)

# IP header processing
def ipheader(header):
    # Header Processing
    src=socket.inet_ntoa(header.src)
    dst=socket.inet_ntoa(header.dst)
    if type(header.data) == dpkt.udp.UDP:
        print("UDP%s:%s=>%s:%s(len:%s)"%(src,header.data.sport,dst,header.data.dport,len(header.data.data)))

# payload
def payload (thex):
    # Payload Processing
    return