Advantages of subprocess over os.system

Question

I have recently came across a few posts on stack overflow saying that subprocess is much better than os.system, however I am having difficulty finding the exact advantages.

Answer 1

There are many reasons, but the main reason is mentioned directly in the docstring:

>>> os.system.__doc__
'Execute the command in a subshell.'

For almost all cases where you need a subprocess, it is undesirable to spawn a subshell. This is unnecessary and wasteful, it adds an extra layer of complexity, and introduces several new vulnerabilities and failure modes. Using subprocess module cuts out the middleman.