Script won't run at boot

[ebolisa]

Hi,

The code below which speaks a wellcome msg if there's an internet connection, runs manually but not at boot through crontab.

Where did I go wrong?
TIA

#!/usr/local/bin/python3

from subprocess import call
from time import sleep

domain = ('www.google.com')

def _call():
    call(['espeak "Welcome John" 2>/dev/null'], shell=True)

def ping(host):
    ret = call(['ping', '-c', '3', '-W', '5', host], stdout=open('/dev/null', 'w'), stderr=open('/dev/null', 'w'))
    return ret

if __name__ == "__main__":
    p = 1
    while p == 1:
      p = ping(domain)
      if(p == 0):
        _call()
      sleep(.3)