Moving from using 'os.system(...)'

[tjones79]

Using os.system to run commands, copy files etc... is generally not a good idea. os.system() does not provide complete or in a few cases, the correct exit status of a program that has crashed. For example, if you are trying to copy a file, and it fails, it will simply return a '1' exit code without telling you exactly why it failed.

There are specific packages built to run shell commands, such as 'shutils' and 'subprocess', we should make use of these instead.