Python WiFi Probe scanner using tcpdump

scan.py

#!/usr/bin/env python2.7
# Based on :https://gist.github.com/LoranKloeze/6b713022619c2b32b32c6400a55a8433

import subprocess
import re
import time

monitor_dev = "wlan1mon"

while True:
    proc = subprocess.Popen(['tcpdump', '-l', '-I', '-i', monitor_dev, '-e', '-s', '256', 'type', 'mgt', 'subtype', 'probe-req'],stdout=subprocess.PIPE)
    patt = '(-\d+)dBm signal antenna 0.+SA:([0-9a-f]+:[0-9a-f]+:[0-9a-f]+:[0-9a-f]+:[0-9a-f]+:[0-9a-f]+) .+(Probe Request) \((.+)\)'
    while True:
        line = proc.stdout.readline()
        if line != '':
            m = re.search(patt, line)
            if m is not None and len(m.groups()) == 4:
                signal = m.group(1).rstrip()
                mac = m.group(2).rstrip()
                ssid = m.group(4).rstrip()
                timestamp = int(time.time())
                print "SSID: ", ssid, "MAC: ", mac, "Signal: ", signal, "Date: ", timestamp
        else:
            break