notepad.py

import keyboard  #pip install keyboard
import os
import time
import subprocess as sp

time.sleep(1)
osCommand = "notepad.exe"
filet = "file.txt"
sp.Popen([osCommand,filet])
time.sleep(2)
for i in range(0,10):
    textoP = "Prueba de texto numero {0}\n".format(i)
    keyboard.write(textoP)
    time.sleep(.5)
keyboard.press("Alt+f")
time.sleep(1)
keyboard.press("s")
time.sleep(1)
keyboard.press("Alt+F4")