Python - how do I call external python programs?

Question

I'll preface this by saying it's a homework assignment. I don't want code written out for me, just to be pointed in the right direction.

We're able to work on a project of our choice so I'm working on a program to be a mini portfolio of everything I've written so far. So I'm going to make a program that the user will input the name of a program (chosen from a given list) and then run the chosen program within the existing shell.

However, I can't really find information on how to call upon external programs. Can anyone point me in the right direction? I considered putting all the code in one long program with a bunch of if loops to execute the right code, but I'd like to make it a BIT more complicated than that.

Answer 1

Check out the subprocess documentation.

Answer 2

Also if you need to pass additional arguments do this:

import subprocess
subprocess.call(["python", "myscript.py", "arg1", "arg2", "argN"])

Answer 3

If you want to call each as a Python script, you can do

import subprocess
subprocess.call(["python", "myscript.py"])
subprocess.call(["python", "myscript2.py"])

But a better way is to call functions you've written in other scripts, like this:

import myscript
import myscript2

myscript.function_from_script1()
myscript2.function_from_script2()

Where function_from_script1() etc are defined in the myscript.py and myscript2.py files. See this page on modules for more information.