old_contents: import psutil
  import subprocess
  
  BYTES_RECV = psutil.net_io_counters().bytes_recv
  
  subprocess.Popen(['bash','./notify.sh',str(BYTES_RECV/1048576)])
  
new_contents: import psutil
  import subprocess
  
  BYTES_RECV = psutil.net_io_counters(pernic=True).get('wlan0').bytes_recv/float(1024)/1024
  
  subprocess.Popen(['bash','./notify.sh',str(BYTES_RECV])
  
subject: Update main.py