Python - PHP Shell Exec

If I run the following via the command line I have no issues:

python /home/forge/default/public/test.py http://csgo.steamanalyst.com/id/195/XM1014-GRASSLAND-WELL-WORN

However if I execute this in php:

shell_exec('python /home/forge/default/public/test.py http://csgo.steamanalyst.com/id/195/XM1014-GRASSLAND-WELL-WORN');

It doesn't run correctly?