import pcapy
from impacket.ImpactDecoder import *

# list all the network devices
pcapy.findalldevs()

max_bytes = 1024
promiscuous = False
read_timeout = 100 # in milliseconds
pc = pcapy.open_live("name of network device to capture from", max_bytes, promiscuous, read_timeout)

pc.setfilter('tcp')

# callback for received packets
def recv_pkts(hdr, data):
  packet = EthDecoder().decode(data)
  print packet

packet_limit = -1 # infinite
pc.loop(packet_limit, recv_pkts) # capture packets

import pcapy
from impacket.ImpactDecoder import *

# list all the network devices
pcapy.findalldevs()

max_bytes = 1024
promiscuous = False
read_timeout = 100 # in milliseconds
pc = pcapy.open_live("name of network device to capture from", max_bytes, promiscuous, read_timeout)

pc.setfilter('tcp')

# callback for received packets
def recv_pkts(hdr, data):
  packet = EthDecoder().decode(data)
  print packet

packet_limit = -1 # infinite
pc.loop(packet_limit, recv_pkts)

http://andrewtrusty.com/

Tried using pypcap but it didn't seem to do anything and I am too lazy to compile python-libpcap.

Requires:
- pcapy python module (http://oss.coresecurity.com/projects/pcapy.html)
- impacket python module (http://oss.coresecurity.com/projects/impacket.html)
- pcap library, for Windows use WinPCap (http://www.winpcap.org/)

Sources:
- http://oss.coresecurity.com/pcapy/doc/pt01.html
- http://www.thescripts.com/forum/post2740081-5.html

Live Packet Capture in Python with pcapy

Python