Graphical Output of MacOS airport Util to analyze Wifi

wifiAnalyzer.py

#!/usr/bin/python
# coding: utf-8

from datetime import datetime, timedelta
import subprocess
import os
import time
import csv
import matplotlib.pyplot as plt

# This is only available on MacOSX
AIRPORT = '/System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport'

def sniffWifi():
    '''
    funtion to grab output of MacOS airport tool and convert it to dictionary
    '''
    wifidata = subprocess.check_output([AIRPORT, '-I']).decode('utf-8')
    wifidict = {'time': datetime.now()}
    for data in wifidata.split('\n')[:-1]:
        try: # if numeric value, parse it
            wifidict[data.split(':')[0].strip()] = int(data.split(':')[1].strip())
        except: # if not, use as text
            wifidict[data.split(':')[0].strip()] = data.split(':')[1].strip()

    return wifidict

def startwifianalyzer(dt=.1, timespan=10,
                        withliveplot=True,
                        withsummaryplot=True,
                        withlogfile=True):
    try:
        zeit = []
        rssi = []
        noise = []
        csvheaderwrote = False

        if withliveplot:
            # Prepare the Live Plot
            plt.ion()
            graph = plt.plot(zeit, rssi)[0]
            datemin = datetime.now()
            datemax = datetime.now() + timedelta(seconds=timespan)
            plt.xlim(datemin, datemax)
            plt.ylim(-98, -12)
            plt.ylabel('RSSI in dBm')
            plt.xlabel('Zeit')

        while True:
            # Grab some WiFi Data
            wifi = sniffWifi()

            # Print Output
            os.system('cls' if os.name == 'nt' else 'clear')
            print('==== Wifi Analyzer: \"%s\" ====' % wifi['SSID'])
            for k, v in wifi.items():
                if k != 'time':
                    print('{:>18}: {:<8}'.format(k, v))
            print("timestamp: %s" % wifi['time'].isoformat(' '))
            print('\'CTRL\' + \'C\' to cancel')

            if withlogfile:
                csvfilename = datemin.isoformat().replace(':','-') + '.csv'
                with open(csvfilename, 'a') as csvfile:
                    writer = csv.writer(csvfile)
                    if not csvheaderwrote:
                        writer.writerow(wifi.keys())
                        csvheaderwrote = True

                    writer.writerow(wifi.values())

            if withliveplot:
                # Live Plot update
                zeit.append(wifi['time'])
                rssi.append(wifi['agrCtlRSSI'])
                noise.append(wifi['agrCtlNoise'])

                graph.set_xdata(zeit)
                graph.set_ydata(rssi)

                if wifi['time'] > datemax: # timescroll
                    plt.xlim(wifi['time']-timedelta(seconds=timespan), wifi['time'])

                plt.gcf().autofmt_xdate()
                plt.draw()
                plt.pause(0.01)

            time.sleep(dt)

    except KeyboardInterrupt:
        print('Canceled')
        plt.close()

    except Exception as e:
        print('Something went wrong:')
        print(e)
        
    if withsummaryplot:
        if len(zeit)>10:
            # Save final plot
            pngfile = ('%s.png' % datemin.isoformat().replace(':','-'))
            print('Saving to %s' % pngfile)

            plt.plot(zeit, rssi, label='RSSI')
            plt.plot(zeit, noise, label='Noise')
            plt.ylabel('dBm')
            plt.xlabel('Zeit')
            plt.title('Wifi \"%s\" (Channel %s)' % (wifi['SSID'], wifi['channel']))
            plt.ylim(-98, -12)
            plt.legend()
            plt.gcf().autofmt_xdate()
            plt.tight_layout()
            plt.savefig(pngfile, dpi=150)
            plt.close()
        else:
            print('Not enough data for summary plot')

if __name__ == "__main__":
    startwifianalyzer()