从PHP执行python脚本（使用apache XAMPP）

Question

I am trying to execute a shell script containing python commands from PHP using exec function in Ubuntu 18.04. The issue is Python script is not able to create a file for writing data.

This is my shell script test.sh

python3 p1.py

This is my python script

with open('trial.txt','w') as file:
    file.write('Hello world')

This is my PHP script

<?php

try{
    $out=exec('test.sh',$output,$status);
    print_r($output);
}
catch(Exception $e)
{
    echo $e;
}?>

I am getting $status as 1. Is there any problem with apache user permissions? Current apache user is www-data. I have given permissions to python script using chmod +x p1.py. This shell script works correctly and creates a new file if it runs from ubuntu terminal. But when executing from PHP, it doesn't work properly.