Call a subprocess function using splunk django or JavaScript

I would like execute an external script from mypage.html write in django and in javascript using the splunk framework To make it the best way is use the subprocess, but I have never use them before. I would like make something like:

var p = subprocess.call({
arguments:   ['my_String'],
workdir: '/home/splunk/myscript.py',
)}
if (p!=null) print "you have execute the script"

But I don't know the syntax, and I have not found documentation online. Thank you