python uptime log

uptime.py

import subprocess, datetime
def writestatus(status):
 f=open("uptime", 'a')
 if status == True:
  string="[" + str(datetime.date.today()) + " " + str(datetime.datetime.now().time()) + "] Site google.co.uk is up \n"
  f.write(string)
  print string
 elif status == False:
  string="[" + str(datetime.date.today()) + " " + str(datetime.datetime.now().time()) + "] Site google.co.uk is down \n"
  f.write(string)
  print string
 f.close
 
ret = subprocess.call("ping -c 1 google.co.uk", shell=True, stdout=open('/dev/null', 'w'), stderr=subprocess.STDOUT)

if ret == 0:
 writestatus(True)
else:
 writestatus(False)