How to call a script with arg, Nexus 9K

Hi. Sorry for formatting, I'm on mobile.

So my problem is pretty straightforward :

When I go in guestshell, I can call my script :

python script.py "argument"

This script sends a request to a website, with this argument as parameter.

And it works. But when I'm not in guestshell :

run guestshell python script.py "argument"

This doesn't work. I steal reach the website but I get a HTTP 500 error, as if the argument given was wrong. My "argument" is a log. So it is a pretty long string.