Is there a way to test the results of an os.system() command in Python?

Question

This is not an exact copy of my code, but it's the only idea I have regarding going about this:

import os
import re

while True:
    com = input()

    if com == "break":#Doesn't matter
        break

    run = os.system(com)
    if run == "'" + com + "' is not recognized as an internal or external command, operable program or batch file.":
        print("Error.")
    else:
        os.system(com)

And it doesn't work. I simply need a way to know if there's a way to test whether an os.system() function works, print the response if it does, and print "Error." otherwise. If it matters, I'm using python 3.9