Perfectly convenient, safe and fast. Pick any two. https://docs.python.org/2/library/subprocess.html

I've told developers that if I catch them writing shell scripts in python they must commit a shell script doing the same set of operations. 2x the work usually dissuades from this type of nonsense.

As usual, "it depends." If you have complex logic, it's generally much cleaner to implement in python.

(If you told me I had to rewrite a working Python script in shell, I'd probably think you were joking. Talk about nonsense.)

'It depends..' is a quagmire for the unwary.

My route is to make a good rule about writing python with more than 'n' os., subprocess. and *.Popen calls automatically requiring shell script counterparts in case we find your need to pythonize unsafe, unreadable and slow|broken|buggy.

There are obviously programs that are better written as a shell script, no denying it! I'm just saying use the best tool for the job. If you're writing complex logic in a shell script, you're probably barking up the wrong tree. Likewise, if all you're doing is calling external programs from python, you're probably doing it wrong.