Problem with executing 2 .py files

[PardodeCela]

I'm trying to run lector.py firstly and gmail.py in second place, but when I try it, the programm finishes at lector.py and don't continue running. I've tried in multiple ways but it's impossible, what is going wrong? Here is the script:

from functools import partial
import os
import lector
import gmail

os.system ("C:/Users/Andrés/Desktop lector.py")
os.system ("C:/Users/Andrés/Desktop gmail.py")