Primary Python running Python files in a chain

I have a process developed step by step with three Python files. I want to make a main Python file that executes the Python files step by step.

I've seen that I could do it with the following code:

import commands
result=commands.getoutput()

But I do not know how to indicate in the function getoutput() within the parentheses that Python files are to be executed sequentially.

The three Python files are in the same folder as the main Python. The names of the files are:

• 00_Main.py
• 01_Extract_Forces_Element_CROD.py
• 02_Order_LC_Elemen_CROD.py
• 03_Element_LC_Forces_CRODS.py

Etoy used to use within the main files the INCLUDE command I do not know if in Python it would work the same or the code above is better