I want to send data from php to python

I've tried to send data from php to python, I found a tutorial from here.

this is the code.

php

<?php
$data = array('1','4','67','34');
$result = shell_exec('python try.py ' . escapeshellarg(json_encode($data)));
$resultData = json_decode($result, true)
var_dump($resultData);
?>

python

#!/Python27/python
import sys, json

# Load the data that PHP sent us
try:
    data = json.loads(sys.argv[1])
except:
    print "ERROR"
    sys.exit(1)

# Send it to stdout (to PHP)
print json.dumps(data)

and output:

array(4) {
  [0]=>
  int(1)
  [1]=>
  int(4)
  [2]=>
  int(67)
  [3]=>
  int(34)
}

I try and succeed, but it's just an integer, I want a string.

I tried to replace the data

$data = array('tiger','dog','cow','lion');

but the result is NULL