The thing sandbox only applies if you use the python_script integration.
Standard python scripts (or other programs) started by command_line sensors should be executed inside the homeassistant container with no other limitations.
That can get quite tricky, since the script runs inside the homeassistant container. Your configuration directory is mounted as /config inside that container. I would start by moving your file there, just for testing. You can continue from there after you get the script to work.
It will depend on your installation method.