# add.py 3 5
import runpy
import sys

# Is it safe to hack sys.argv like this?
orig_argv = sys.argv
sys.argv = "add.py 3 5".split()
runpy.run_path("add.py", run_name="__main__")
sys.argv = orig_argv

# And is it safe to hack sys.stdout if we want to get its output?