Python库对localhost不可见

Python Pillow在我的本地环境(python2.7)中可用,但是当我尝试使用PHP在localhost内部运行Python脚本时,返回以下错误,

有人能帮忙吗

阿杰克斯 (请求)

 $.ajax({
              type: "POST",
              url: 'http:/localhost/simulator/data.php',
              dataType: "json",
                     success: function(out)
                     {
                      print("sucess!");
                      print(out);
                     }

    });

菲律宾比索 (data.php)

<?php

$result =  shell_exec('python ./index.py 2>&1 ');
echo json_encode($result);
?>

python

#!/usr/bin/env python
import sys,os,json,cv2,pickle
import PIL
from PIL import Image

if __name__ == '__main__':
    print("got")

错误

Traceback (most recent call last):
  File "./import.py", line 3, in <module>
    import PIL
ImportError: No module named PIL