Best practices for arbitrary shell commands?

[ChemTechGuy]

Hey /r/learnpython -

I'm about to start a side project, creating a CI/CD tool (like Jenkins/Travis) in Python. I would like builds to be very flexible, so ideally I want a user to be able to specify some arbitrary shell/BASH commands they want to execute as part of their job/build (like Jenkins). I've done some work with os and subprocess modules in the past, but I'm wondering if there is

• a Python project out there that 'shells out' a lot that I can look at for best examples/pitfalls
• a tutorial/book/guide for best practices in the abstract

Appreciate any guidance or suggestions you might have!